Demographic characteristics and delayed neurological sequelae risk factors in carbon monoxide poisoning.

AIM: Carbon monoxide (CO) is a colorless, odorless gas and tasteless. CO poisoning (COP) is one of the most frequently encountered inhalation poisonings. The most common cause of morbidity in COP is delayed neurological sequelae (DNS). DNS is the occurrence of neuropsychiatric findings within 2-240 days after discharge of patients with COP and there are no definitive diagnostic criteria. The aim of our study is; to determine the risk factors and incidence of DNS. METHOD: Our study is a retrospective, observational study. Patients with the diagnosis of COP in the emergency department between 2015 and 2016 were included in the study. Patients age, gender, findings in the initial physical examination (PE) and neurological examination (NE), blood carboxyhemoglobin (COHb) level, relation between hyperbaric oxygen (HBO) treatment and DNS were assessed. RESULTS: Total of 72 patients were included in the study. Mean age was 33.43 ±â€¯20.89. It was determined that pathological findings in the initial NE are a significant predictive factor for DNS (Odds ratio 18.600, p:0.004). Significant relation between NE and HBO treatment was present (p:00.1). There was no statistically significant relationship between initial COHb level and receiving HBO treatment (p:0.9). Median COHb level of patients with DNS was 30 (min:10, max: 43), median COHb level of patients without DNS was 25 (min:10, max:44) and there was no statistically significant relationship between the two groups according to COHb levels (p:0.7). CONCLUSION: Pathological findings in the initial neurological examination had a predictive value for delayed neurological sequelae in patients with carbon monoxide poisoning.

The asymmetry of neural symptoms in Wilson's disease patients detecting by diffusion tensor imaging, resting-state functional MRI, and susceptibility-weighted imaging.

Objective: To investigate the cause of the motor asymmetry in Wilson's disease (WD) patients using functional MRI. Methods: Fifty patients with WD and 20 age-matched healthy controls were enrolled. Neurological symptoms were scored using the modified Young Scale. All study subjects underwent diffusion tensor imaging (DTI), susceptibility-weighted imaging (SWI), and resting-state functional MRI (rs-fMRI) of the brain. Six regions of interest (ROI) were chosen. Fiber volumes between ROIs on DTI, corrected phase (CP) values on SWI, amplitude of low-frequency fluctuation (ALFF), and regional homogeneity (REHO) values on rs-fMRI were determined. Asymmetry index (right or left value/left or right value) was evaluated. Results: Asymmetry of rigidity, tremor, choreic movement, and gait abnormality (asymmetry index = 1.33, 1.39, 1.36, 1.40), fiber tracts between the GP and substantia nigra (SN), GP and PU, SN and thalamus (TH), SN and cerebellum, head of the caudate nucleus (CA) and SN, PU and CA, CA and TH, TH and cerebellum (asymmetry index = 1.233, 1.260, 1.269, 1.437, 1.503, 1.138, 1.145, 1.279), CP values in the TH, SN (asymmetry index = 1.327, 1.166), ALFF values, and REHO values of the TH (asymmetry index = 1.192, 1.233) were found. Positive correlation between asymmetry index of rigidity and fiber volumes between the GP and SN, SN and TH (r = .221, .133, p = .043, .036), and tremor and fiber volumes between the CA and TH (r = .045, p = .040) was found. Conclusions: The neurological symptoms of patients with WD were asymmetry. The asymmetry of fiber projections may be the main cause of motor asymmetry in patients with WD.

Intervención fisioterapéutica en el manejo de pacientes con artritis reumatoide: una revisión sistemática / Physiotherapy intervention in the management of rheumatoid arthritis patients: A systematic review

Objetivo: Realizar una revisión de la evidencia disponible y determinar el tratamiento fisioterapéutico para pacientes con artritis reumatoide. Estrategia de búsqueda: Se realizó la búsqueda de ensayos clínicos aleatorizados, publicados entre el año 2000 y el 2015 en las siguientes bases de datos: PubMed, ScienceDirect y Cochrane Library. Seguido de la evaluación de calidad metodológica con 2 escalas PEDro y SIGN. Los ECA debían incluir intervención fisioterapéutica (ejercicio físico, agentes físicos, telerrehabilitación o técnicas alternativas), ser aplicado en pacientes con artritis reumatoide y que midieran las siguientes variables: dolor, rigidez articular, funcionalidad y/o calidad de vida. Selección de estudios: Se incluyeron 28 ECA, de los cuales 21 eran intervenciones con ejercicio terapéutico, 5 agentes físicos, una técnica alternativa y una telerrehabilitación. Síntesis de resultados: La evidencia muestra que el ejercicio terapéutico tiene un impacto significativo en la capacidad funcional en funciones de la mano, movilidad y desplazamientos. El uso agentes físicos no mostró una diferencia significativa entre los grupos, pero sí al comienzo y final de la intervención. El uso de taichi como técnica alternativa evidencia mejoría tanto física como mental y una intervención de actividad física basada en Internet con supervisión individualizada, equipo de ejercicio y acompañamiento es eficaz como estrategia de intervención. Conclusiones: Desde la fisioterapia, hay diversas intervenciones para los pacientes con artritis reumatoide, dentro de los cuales el más utilizado y con mayores efectos positivos es el ejercicio terapéutico

Objective: To evaluate and critical review the available scientific evidence and determine the physical therapy treatment for patients with rheumatoid arthritis (RA) Search strategy: Systematic searches were conducted for randomized clinical trials (RCTs) published between 2000 and 2015 in the following databases: PubMed, ScienceDirect and Cochrane Library. Following the evaluation of methodological quality with two scales PEDro and SIGN. RCTs should include physiotherapy intervention (physical exercise, physical agents, tele-rehabilitation or alternative techniques), be applied in patients with RA and that measured the following variables: pain, stiffness, function and/or quality of life. Study selection: 28 RCTs were included; 21 correspond to interventions with therapeutic exercise, 5 with physical agents, 1 to alternative techniques and 1 tele-rehabilitation. Synthesis of results: Evidence shows that therapeutic exercise has a significant impact on functional capacity, especially in hand function, mobility and displacement. Physical agents showed no statistical difference between the groups, but does at the beginning and end of the intervention. The Taichi as an alternative and complementary to traditional intervention technique improves physical and mental condition. Finally, physical activity based on Internet with one supervision, exercise equipment and support is effective as an intervention strategy. Conclusions: Based on the results of this review can be established that since there are different physical therapy interventions for patients with RA, within which the most widely used and with greater positive effects is the therapeutic exercise

Somatomotor mu rhythm amplitude correlates with rigidity during deep brain stimulation in Parkinsonian patients.

OBJECTIVE: Parkinsonian patients have abnormal oscillatory activity within the basal ganglia-thalamocortical circuitry. Particularly, excessive beta band oscillations are thought to be associated with akinesia. We studied whether cortical spontaneous activity is modified by deep brain stimulation (DBS) in advanced Parkinson's disease and if the modifications are related to the clinical symptoms. METHODS: We studied the effects of bilateral electrical stimulation of subthalamic nucleus (STN) on cortical spontaneous activity by magnetoencephalography (MEG) in 11 Parkinsonian patients. The artifacts produced by DBS were suppressed by tSSS algorithm. RESULTS: During DBS, UPDRS (Unified Parkinson's Disease Rating Scale) rigidity scores correlated with 6-10 Hz and 12-20 Hz somatomotor source strengths when eyes were open. When DBS was off UPDRS action tremor scores correlated with pericentral 6-10 Hz and 21-30 Hz and occipital alpha source strengths when eyes open. Occipital alpha strength decreased during DBS when eyes closed. The peak frequency of occipital alpha rhythm correlated negatively with total UPDRS motor scores and with rigidity subscores, when eyes closed. CONCLUSION: STN DBS modulates brain oscillations both in alpha and beta bands and these oscillations reflect the clinical condition during DBS. SIGNIFICANCE: MEG combined with an appropriate artifact rejection method enables studies of DBS effects in Parkinson's disease and presumably also in the other emerging DBS indications.

Differential involvement of striato- and cerebello-thalamo-cortical pathways in tremor- and akinetic/rigid-predominant Parkinson's disease.

Parkinson's disease (PD) presents clinically with varying degrees of resting tremor, rigidity, and bradykinesia. For decades, striatal-thalamo-cortical (STC) dysfunction has been implied in bradykinesia and rigidity, but does not explain resting tremor in PD. To understand the roles of cerebello-thalamo-cortical (CTC) and STC circuits in the pathophysiology of the heterogeneous clinical presentation of PD, we collected functional magnetic resonance imaging (fMRI) data from 17 right-handed PD patients [nine tremor predominant (PDT) and eight akinetic-rigidity predominant (PDAR)] and 14 right-handed controls while they performed internally-guided (IG) sequential finger tapping tasks. The percentage of voxels activated in regions constituting the STC and CTC [divided as cerebellar hemisphere-thalamo-cortical (CHTC) and vermis-thalamo-cortical (CVTC)] circuits was calculated. Multivariate analysis of variance compared the activation patterns of these circuits between study groups. Compared to controls, both PDAR and PDT subjects displayed an overall increase in the percentage of voxels activated in both STC and CTC circuits. These increases reached statistical significance in contralateral STC and CTC circuits for PDT subjects, and in contralateral CTC pathways for PDAR subjects. Comparison of PDAR and PDT subjects revealed significant differences in ipsilateral STC (P=0.005) and CTC (P=0.043 for CHTC and P=0.003 for CVTC) circuits. These data support the differential involvement of STC and CTC circuits in PD subtypes, and help explain the heterogeneous presentation of PD symptoms. These findings underscore the importance of integrating CTC circuits in understanding PD and other disorders of the basal ganglia.

Motion in response to the hypnotic suggestion of arm rigidity: a window on underlying mechanisms.

Among hypnotized subjects passing a challenge suggestion of arm rigidity, how might patterns of motor activity (strategies) contribute to the illusion that the elbow cannot be bent? Kinematic analyses of upper limb and trunk were performed. Nonhypnotized subjects carefully enacted a set of prescribed strategies typifying responses possibly adopted by a hypnotized subject. Profile analysis showed striking heterogeneity of response in hypnotic subjects. Half of participants showed no perceivable strategy consistent with the hypothesis that subjects hallucinate the suggestion and so do not engage the motor periphery. Equally common were subtle oscillations or trembling of the arm implying that motion resembling difficulty in bending was initiated. This can be misperceived as unintentional and thus evidence of inability to bend. The lack of a motor strategy is more consistent with dissociated-control theory, whereas the trembling response is more consistent with social-cognitive and dissociated-experience theories.

Spinal cord stimulation to abort painful spasms of atypical stiff limb syndrome.

Stiff limb syndrome (SLS) is a rare chronic condition which can result in significant debility. We report the case of a 44-year-old man suffering from severe painful spasms in his right leg with a diagnosis of SLS. He had been initially treated for his pain with a spinal cord stimulator but presented with exacerbation of pain secondary to a lead fracture for which he underwent revision of the stimulator. Postoperative programming unexpectedly resulted in not only control of his pain but also an ability to abort his spasmodic episodes related to SLS. To our knowledge, spinal cord stimulation has not been previously used for SLS and our report opens up another avenue for this rare condition. We provide a brief overview of SLS and propose an underlying mechanism for the observed phenomenon.

Anatomy of a hypnotic response: Self-report estimates, actual behavior, and physiological response to the hypnotic suggestion for arm rigidity.

The present study closely examines subject response to the arm-rigidity item of the HGSHS:A. Subject behavior, subject self-report, and surface EMG of the biceps and triceps muscles were monitored. Two distinct ways of passing the item were observed and verified by EMG recordings: some subjects (tremblers) exerted muscular effort to bend the arm and kept it rigidly straight. Others (nontremblers) passively kept the arm straight without exerting muscular effort to bend, even though they reported exerting effort to bend their arm. These two behaviorally and physiologically different methods of passing the item support the idea of individual differences in hypnotic responding and suggest that subjects may be using different mental processes to pass the item.

Pathophysiology of motor fluctuations in Parkinson's disease.

Loss of dopamine neurons in Parkinson's disease (PD) initiates a complex stream of effects that results in the development of tremor, bradykinesia, and rigidity. While levodopa remains the most effective drug for the symptomatic treatment of PD, its chronic administration is associated with the development of motor fluctuations and dyskinesias. The risk of developing motor fluctuations has been linked to disease severity, dosage of levodopa, and the age of the patient. A recent body of preclinical data has demonstrated that alterations in dopaminergic tone as well as in treatment patterns results in cellular adaptations, including alterations in gene expression. This body of preclinical data suggests that nonphysiological, pulsatile stimulation of dopamine receptors induces the development of motor fluctuations and dyskinesias and raises the possibility that nonpulsatile stimulation of dopamine receptors (continuous dopaminergic stimulation) might induce fewer fluctuations. We discuss the theory of continuous dopaminergic stimulation and its implications for the management of motor fluctuations in patients with advanced and early PD.

Progression of Parkinson's disease following thalamic deep brain stimulation for tremor.

We assessed the long-term effect of thalamic deep brain stimulation (DBS) on motor symptoms and progression of Parkinson's disease (PD) in PD patients treated for resting and postural/action tremor. Thalamic DBS was performed in 17 patients with treatment-resistant resting and postural/action tremor. Nine patients were available for follow-up examination a mean of 5.5 years after surgery. Three had tremor-dominant PD. DBS produced marked improvement in resting and postural/action tremor in target upper extremity in all 9 patients, which persisted unchanged at the time of the last follow-up visit 5.5 years after surgery. PD severity with DBS 'on' and 'off' 1 year after surgery was compared to PD severity at the last follow-up visit using UPDRS (Unified Parkinson's Disease Rating Scale) III motor scores and individual motor item subscores. Patients were tested while on medication. There was no significant worsening of tremor, rigidity, speech, postural stability, gait, or axial bradykinesia with DBS either on or off at the last follow-up visit compared to the 12-month visit. UPDRS III motor scores were unchanged. However, global assessment of PD progression and increased mean L-dopa dose and L-dopa equivalent daily dose at the time of last follow-up visit indicated that a progression of PD had occurred.

How do parkinsonian signs return after discontinuation of subthalamic DBS?

OBJECTIVE: To study the reappearance of the clinical signs of PD when subthalamic nucleus (STN) deep brain stimulation (DBS) was turned off. METHOD: The authors studied 35 patients treated with STN DBS 6.7 +/- 3.3 months (mean +/- SD) after implantation. All were clinically improved. Twenty-four had not required any antiparkinsonian medication for many months and 11 were in "practically defined off" conditions when studied. Unified Parkinson's Disease Rating Scale (UPDRS) motor scores were assessed at baseline and 5, 15, 30, 60, 90, 120, 150, 180, and 240 minutes after switching off STN DBS. RESULTS: A sequential pattern of return of parkinsonian signs was observed, with a fast worsening of tremor within minutes, followed by a smoother, slower worsening of bradykinesia and rigidity over half an hour to an hour, and finally a slow and steady worsening of axial signs over 3 to 4 hours. Ninety percent of the UPDRS motor score worsening was reached after 2 hours. When switching STN DBS "on" again, all motor UPDRS subscores improved with a similar pattern, but faster than their rate of worsening, especially for axial signs. CONCLUSIONS: STN DBS may act by different mechanisms on the four major parkinsonian signs. At least 3 hours off STN DBS is needed to estimate the clinical effect of stimulation.

Worry and heart rate variables: autonomic rigidity under challenge.

[Borkovec, T. D. (1994). Worrying: perspectives on theory, assessment and treatment (pp. 5-34). West Sussex: Wiley] proposes that the cognitive activity of worry restricts autonomic nervous system activity, producing autonomic rigidity. Autonomic rigidity affects both sympathetic nervous system [Behav. Res. Ther. 28 (1990) 69.] and parasympathetic nervous system activity [Behav. Ther. 26 (1995)457.]. Three experiments investigated the relationship between worry and autonomic system activity as indexed by heart activity measures. In the first experiment, we measured average heart rate when worriers were required to perform a public speaking task. No difference was found in heart rate between worriers and controls. The second and third experiments measured average heart rate and heart period variability (HPV) in worriers and controls during relaxation, non-stressful cognitive tasks, worried thinking, and aversive imagery conditions. There was no support for the autonomic rigidity view as worriers did not respond differently to non-worriers. These findings challenge the view that autonomic rigidity applies generally to worry.

The effect of Trager therapy on the level of evoked stretch responses in patients with Parkinson's disease and rigidity.

OBJECTIVE: To quantify changes of evoked stretch responses (ESR) in the most rigid arm of patients with Parkinson's disease (PD) after Trager therapy. METHODS: Gentle rocking motion associated with this type of manual therapy was imparted to the upper limbs and body of 30 patients for 20 minutes. A pretest and 2 posttests (at 1 and 11 minutes after the treatment, respectively) were performed, consisting of electromyographic (EMG) recordings of the flexor carpi radialis and extensor digitorum communis while the patient's wrist was passively flexed and extended with an amplitude of 60 degrees and a frequency of 1 Hz. Patients received the treatment on the most rigid side of their bodies (ipsi-group) or on the contralateral side (contra-group). Half of patients in each group received the treatment while lying supine on a massage table (ipsi- and contra-supine) or sitting in a chair (ipsi- and contra-sitting). RESULTS: In general, the level of ESR were reduced by 36% immediately after treatment and remained 32% lower than pretest values 11 minutes after treatment (F = 41.45, P <.05). Patients who received the treatment lying supine benefited from a 42% reduction of ESR (F = 4.07, P <.05). The side on which the treatment was performed did not significantly influence the outcome of the treatment (F = 0.50, P >.05). However, post hoc analysis of the triple interaction (test x side x position) indicated that the sitting position was much less efficient for sustained contralateral effect (P >.05). CONCLUSIONS: Results from the present study strongly suggest that it is possible to modify the level of ESR by using Trager therapy. This stretch reflex inhibition may induce a reduction of the muscle rigidity seen in these patients. The present results may eventually lead to the development of a specific complementary therapy for patients with Parkinson's disease and rigidity.

Electrical stimulation of the brain in Wilson-Konovalov hepatocerebral dystrophy (a neuromorphological and neurophysiological analysis).

Stereotaxic surgery was performed in 27 patients. Complete elimination of or significant reductions in hyperkinesia were obtained in 17 cases; five patients died. There was no correlation between the severity of clinical manifestations of hepatocellular dystrophy and the relatively normal quantitative measures of cortical and subcortical biopotentials, which were produced on a background of microstructural changes affecting neurons in these regions. It is suggested that qualitative significance of these biopotentials is that they carry an excess pathological spike activity resulting in hyperkinesia. This is supported by the fact that hyperkinesia was suppressed after surgical destruction of the ventrolateral nucleus of the thalamus and subthalamic structures.

Subthalamic nucleus stimulation for Parkinson disease: benefits observed in levodopa-intolerant patients.

OBJECT: A blinded evaluation of the effects of subthalamic nucleus (STN) stimulation was performed in levodopa-intolerant patients with Parkinson disease (PD). These patients (Group I, seven patients) were moderately or severely disabled (Hoehn and Yahr Stages III-V during the off period), but were receiving only a small dose of medication (levodopa-equivalent dose [LED] 0-400 mg/day) because they suffered unbearable side effects. The results were analyzed in comparison with those obtained in patients with advanced PD (Group II, seven patients) who were severely disabled (Hoehn and Yahr Stages IV and V during the off period), but were treated with a large dose of medication (500-990 mg/day). METHODS: The patients were evaluated twice at 6 to 8 months after surgery. To determine the actual benefits afforded by STN stimulation to their overall daily activities, the patients were maintained on their medication regimen with optimal doses and schedules. Stimulation was turned off overnight for at least 12 hours. It was turned on in the morning (or remained turned off), and each patient's best and worst scores on the Unified Parkinson's Disease Rating Scale during waking daytime activity were recorded as on- and off-period scores, respectively. The order of assessment with respect to whether stimulation was occurring was determined randomly. The STN stimulation markedly improved daily activity and total motor scores in Group I patients. The percentage time of immobility (Hoehn and Yahr Stages IV and V) became 0% in patients who were intermittently immobile while not receiving stimulation. Improvements were demonstrated in tremor, rigidity. akinesia, and gait subscores. The STN stimulation produced less marked but still noticeable improvements in the daily activity and total motor scores in Group II patients. The percentage time of immobility as well as the LED was reduced in patients who displayed intermittent immobility with pronounced motor fluctuations while not receiving stimulation. Improvements were demonstrated in tremor, rigidity, and dyskinesia subscores in these patients. In contrast, STN stimulation did not improve the overall daily activities at all in patients who had become unresponsive to a tolerable dose of levodopa and were continuously immobile, even though these patients' tremor and rigidity subscores were still improved by stimulation. CONCLUSIONS: Consistent with earlier findings, the great benefit of STN stimulation in levodopa-intolerant patients is that STN stimulation can reduce the level of required levodopa medication. This suggests that STN stimulation could be a therapeutic option for patients with less-advanced PD by allowing levodopa medication to be maintained at as low a dose as possible, and to prevent adverse reactions to the continued use of large-dose levodopa.

Experimental parkinsonism in primates.

Early in the 1960s the primate model of Parkinson's disease was first introduced by placing an electrolytic lesion in the midbrain. In the 1980s, a dopaminergic neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was accidentally shown to induce parkinsonism in humans, and subsequently was confirmed to reproduce an almost perfect model of parkinsonism in primates. In the late 1980s chemical manipulations of the basal ganglia were shown to induce parkinson symptoms, especially dyskinesia, and more recently, chemical lesioning of the pedunculopontine tegmental nucleus has also been shown to induce parkinsonism. We still do not have a perfect animal model of parkinsonism, however, these models have offered excellent opportunities to study the basic mechanisms in parkinsonism and the function of the basal ganglia.

Subthalamic prelemniscal radiation stimulation for the treatment of Parkinson's disease: electrophysiological characterization of the area.

Previous reports have provided evidence of a reticulo-thalamic system, extending from the mesencephalic reticular formation (MRF) to the ventrolateral thalamus (VL), involved in the production of tremor. In humans, a funnel of fibers in the posterior subthalamus named the prelemniscal radiations (Raprl) has been described as an exquisite target to treat tremor in cases of Parkinson's disease. In the present study, a group of 14 patients suffering from Parkinson's disease, with prominent unilateral tremor and rigidity, were implanted with tetrapolar depth brain stimulation (DBS) electrodes in Raprl to perform chronic electrical stimulation (ES) for the treatment of patient symptoms. Electrodes were left externalized to corroborate their placement throughout MRI studies and also to perform the following electrophysiological battery: (a) recording of somatosensory-evoked responses (SEP) through different electrode contacts and scalp by means of a paradigm to study the attention process; (b) evoking scalp EEG responses by stimulation with low (3 cps, 6 cps) and high (60-120 cps) frequencies with stimuli delivered through different electrode contacts, and (c) studying recovery cycle (RC) potentials in the Raprl while the upper MRF was being stimulated and, conversely, the RC in MRF while Raprl was being stimulated, before and after subacute Raprl stimulation. Thereafter, the electrodes were internalized and connected to a pulse generator (IPG) to carry on chronic ES, while the effects of stimulation were determined through a quantitative evaluation that measured phasic and tonic muscular activity with EMG recordings during different motor tasks. Results indicate the following: (a) that late, but not early, SEP components were recorded in Raprl and modulated in different attentive conditions; (b) that bilateral recruiting responses and spike and wave complexes were elicited by Raprl through low-frequency stimulation, while bilateral positive DC shifts induced by high-frequency stimulation were recorded, similar to those obtained in animals from MRF, and (c) that Raprl-ES induced RC inhibition at Raprl, but Raprl ES did not change MRF-RC. Long-term Raprl-ES induced a significant decrease in tremor and rigidity. It was concluded that Raprl represents a subthalamic circuit electrophysiologically related to MRF in the genesis of tremor and rigidity and in the process of selective attention. Raprl-ES induced a significant improvement in tremor and rigidity by causing inhibition of the stimulated area.

Long-term effect of electrostimulation of the subthalamic nucleus in bradykinetic-rigid Parkinson's disease.

The motor effects of unilateral stimulation of the subthalamic nucleus on hypokinesia were studied in two patients 58 and 52 years old, both modified Hoehn and Yahr 2.5, at 16 and 15 months after the implantation of a quadripolar electrode (Medtronic). Motor UPDRS, time in the pegboard test, walking time, tapping, and serial reaction times were recorded. Chronic unilateral stimulation was associated with reversible improvement of measures of reaction time and hypokinesia > 1 year after the stereotactic electrode implantation. The beneficial effect was mainly contralateral to the stimulation. However, improvement of axial functions was also observed (phonation, walking).

Spectroscopic imaging of frontal neuronal dysfunction in hyperekplexia.

We used proton magnetic resonance spectroscopic imaging (MRSI) to assess in vivo cortical neuronal involvement in hyperekplexia. Cerebral neuronal function was measured using proton MRSI in four unrelated patients with hyperekplexia and 20 healthy controls. All patients had the major form of hyperekplexia, with additional atypical clinical features in two of them. Family history was positive in three patients and absent in one. The neuronal marker N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine (Cr) were measured in frontal, central and parietal areas. The MRSI showed a reduction of the relative resonance intensity of NAA/(Cr + Cho) in frontal and central regions in three patients, and in the right frontal region of the fourth. In one patient a second MRSI showed normal relative NAA resonance intensities over both temporal lobes as well as in the brainstem. In two subjects the topography of EEG abnormalities in the frontal lobes coincided with the MRSI findings. This proton MRSI study indicates the presence of frontal neuronal dysfunction in hyperekplexia. Whether this represents cortical dysfunction or an epiphenomenon of diencephalic or brainstem abnormalities remains open. However, the observation of normal proton MRSI in the temporal regions and brainstem in one of the patients seems to concur with the hypothesis of a facilitatory role of cortical dysfunction within areas of sensorimotor representation in the generation of the pathological startle reaction in hyperekplexia.

Gamma knife radiosurgery as a lesioning technique in movement disorder surgery.

OBJECT: To increase knowledge of the safety and efficacy of the use of gamma knife radiosurgery in patients with movement disorders, the authors describe their own experience in this field and include blinded independent assessments of their results. METHODS: Fifty-five patients underwent radiosurgical placement of lesions either in the thalamus (27 patients) or globus pallidus (28 patients) for treatment of movement disorders. Patients were evaluated pre- and postoperatively by a team of observers skilled in the assessment of gait and movement disorders who were blinded to the procedure performed. The observers were not associated with the surgical team and concomitantly and blindly also assessed a group of 11 control patients with Parkinson's disease who did not undergo any surgical procedures. All stereotactic lesions were made with the Leksell gamma unit using the 4-mm secondary collimator helmet and a single isocenter with maximum doses from 120 to 160 Gy. Clinical follow-up evaluation indicated that 88% of patients who underwent thalamotomy became tremor free or nearly tremor free. Statistically significant improvements in performance were noted in the independent assessments of Unified Parkinson's Disease Rating Scale (UPDRS) scores in the patients undergoing thalamotomy. Of patients undergoing pallidotomy who had exhibited levodopainduced dyskinesias, 85.7% had total or near-total relief of that symptom. Clinical assessment indicated improvements in bradykinesia and rigidity in 64.3% of patients who underwent pallidotomy. Independent blinded assessments did not reveal statistically significant improvements in Hoehn and Yahr scores or UPDRS scores. On the other hand, 64.7% of patients showed improvements in subscores of the UPDRS, including activities of daily living (58%), total contralateral score (58%), and contralateral motor scores (47%). Total ipsilateral score and ipsilateral motor scores were both improved in 59% of patients. One (1.8%) of 55 patients experienced a homonymous hemianopsia 9 months after pallidotomy due to an unexpectedly large lesion. No other complications of any kind were seen. Neuropsychological test scores that were obtained for the combined pallidotomy and thalamotomy treatment groups preoperatively and at 6 months postoperatively demonstrated an absence of cognitive morbidity. Follow-up neuroimaging confirmed correct lesion location in all patients, with a mean maximum deviation from the planned target of 1 mm in the vertical axis. Measurements of lesions at regular intervals on postoperative magnetic resonance images demonstrated considerable variability in lesion volumes. The safety and efficacy of functional lesions made with the gamma knife appear to be similar to those made with the assistance of electrophysiological guidance with open functional stereotactic procedures. CONCLUSIONS: Functional lesions may be made safely and accurately using gamma knife radiosurgical techniques. The efficacy is equivalent to that reported for open techniques that use radiofrequency lesioning methods with electrophysiological guidance. Complications are very infrequent with the radiosurgical method. The use of functional radiosurgical lesioning to treat movement disorders is particularly attractive in older patients and in those with major systemic diseases or coagulopathies; its use in the general movement disorder population seems reasonable as well.