Heart rate variability in Parkinson's disease unaffected by deep brain stimulation.

OBJECTIVES: Our aim was to investigate the impact of subthalamic nucleus deep brain stimulation (STN-DBS) on the cardiovagal control of patients with advanced Parkinson's disease. MATERIALS AND METHODS: Twenty-four patients (mean age: 62.1 ± 9.4 years) were examined 3 days before and 6 months after DBS by a questionnaire, blood pressure monitoring and a battery of neurophysiological tests: time domain analysis of RR interval variation during normal and deep breathing (DB), Valsalva manoeuvre, and tilt test. By off-line, performed frequency domain analysis of heart rate variation, total power (TP), low frequency band (LF) band, high-frequency (HF) band, and their normalized units were estimated. The neurophysiological measurements were compared to those of 24 healthy controls. RESULTS: The values of time domain variables were pre- and postoperatively lower in patients than in controls. A significant reduction was found in LF band after the implantation. Orthostatic hypotension was present in 45.8% of the patients preoperatively and 12.5% postoperatively. There was no correlation between DBS-related changes of motor function and corresponding neurophysiological measurements, but patients with more than 60% motor improvement had higher time domain parameters' values than the others. CONCLUSIONS: STN-DBS offered no considerable impact on autonomic cardiovascular control.

Deep brain stimulation for secondary dystonia: results in 8 patients.

BACKGROUND: Dystonia is a medically intractable condition characterized by involuntary twisting movements and/or abnormal postures. Deep Brain Stimulation (DBS) has been used successfully in various forms of dystonia. In the present study, we report on eight patients with secondary dystonia, treated with DBS in our clinic. METHOD: Eight patients (five males, three females) underwent DBS for secondary dystonia. The etiology of dystonia was cerebral palsy (n = 2), drug-induced (n = 1), post encephalitis (n = 2) and postanoxic dystonia (n = 3). The functional capacity was evaluated before and after surgery with the use of Burke-Fahn-Mardsen Dystonia Rating Scale (BFM scale), both movement and disability scale (MS and DS, respectively). The target for DBS was the globus pallidus internus (GPi) in 7 patients and in one patient, with postanoxic damaged pallidum, the ventralis oralis anterior (Voa) nucleus. Brain perfusion scintigraphy using Single Photon Emission Computed Tomography (SPECT) was performed in two separate studies for each patient, one in the "off-DBS" and the other in the "on-DBS" state. FINDINGS: Postoperative both MS and DS scores were found to be significantly lower compared to preoperative scores (p = 0.018 and p = 0.039, respectively). Mean improvement rate after DBS was 41.4% (0-94.3) and 29.5% (0-84.2) in MS and DS scores, respectively. The SPECT Scan, during the "on-DBS" state, showed a decrease in regional cerebral blood flow (rCBF), compared to the "off-DBS" state. CONCLUSIONS: Our results seem promising in the field of secondary dystonia treatment. More studies with greater number of patients and longer follow-up periods are necessary in order to establish the role of DBS in the management of secondary dystonia. Finally, the significance of brain SPECT imaging in the investigation of dystonia and functional effects of DBS should be further evaluated.

In-hospital direct cost of acute ischemic and hemorrhagic stroke in Greece.

OBJECTIVES: The geographic inequity and the wide variation in the patterns of care of stroke found across Europe together with the lack of health economics evaluation in Greece led to this prospective study, aiming to provide data on in-hospital direct cost of patients with an acute stroke in Greece, and to identify independent prognostic factors. METHODS: Demographic and clinical data were recorded on 429 consecutive patients with an acute ischemic or hemorrhagic stroke admitted to a tertiary care hospital in Greece during a period of 18 months. The costs incurred were estimated using the official financial charts listing in euro (euro), the real expenditure of all hospital departments. RESULTS: The direct in-hospital cost for all stroke cases was 1,551,445euro for a total of 4674 days (331.9euro per day in-hospital). The mean in-hospital cost per stroke patient was 3624.9euro (+/-2695.4). Hemorrhagic strokes were significantly more expensive than the ischemic strokes [mean 5305.4 (+/-4204.8)euro and 3214.5 (+/-1976.2)euro, respectively) and lacunar strokes the least expensive among ischemic stroke subtypes. The length of stay was highly correlated with in-hospital total cost. Multivariate linear regression analysis showed that admission ward, stroke severity on admission, stroke type and status discharge were independent predictors of cost. CONCLUSIONS: Purchasers in our health services should differentiate in their cost estimates and pricing schemes between types of cerebrovascular events. Future studies should focus on modifiable factors related, not only with stroke characteristics, but also with operational policies of hospitals, that may influence length of stay.

Co-occurrence of brain tumours and demyelination of the central nervous system: coincidence or interrelation?

The co-occurrence of a brain tumour and demyelinating disease of the central nervous system (CNS) constitutes a rare clinical entity. We herein report the incidence of meningioma and CNS non-specific demyelination in a patient with a 6-year history of operated brain tumour (meningioma). Our case bolsters the argument that in at least some cases, the occurrence of a brain tumour could predispose to CNS non-specific demyelination.

Peripheral large nerve fibre function in patients with chronic plaque psoriasis.

Accumulating evidence suggests the involvement of neurogenic inflammation in the pathogenesis of psoriasis. Moreover, the concomitant occurrence of peripheral neuropathy has been reported in several psoriatic patients. Thus, the aim of the present study was to answer the question whether an impairment of peripheral large nerve fibre function may exist in psoriasis. Thirty-two patients with severe and generalized chronic plaque psoriasis and 32 sex- and age-matched healthy controls were evaluated by detailed clinical neurological and standard neurophysiological examination. The latter included motor nerve conduction study of one nerve in the upper and one in the lower extremities and sensory nerve conduction study of one nerve in the upper and two in the lower extremities. Neurological examination failed to demonstrate any clinical evidence of large fibre neuropathy. Furthermore, all values of the examined neurophysiological parameters were within normal limits; comparisons of the corresponding mean values in the patient and the control group showed no statistically significant differences. These findings demonstrate no measurable abnormalities of the peripheral large nerve fibres in psoriatic patients and therefore an association of psoriasis with peripheral large fibre neuropathy cannot be suggested.

Effects of carotid endarterectomy on motor evoked potentials elicited by transcranial magnetic stimulation.

PURPOSE: To investigate the within 3 days effects of carotid endarterectomy (CEA) on functional status of the central motor system in patients with carotid stenosis by means of transcranial magnetic stimulation (TMS). PATIENTS AND METHOD: We studied 30 consecutive patients, 20 males and 10 females with a mean age of 69.2+/-7.1 years, who underwent CEA for symptomatic carotid stenosis. All patients had suffered an ischemic attack 6 months prior to the operation. Two TMS studies, one before and one shortly after CEA were performed on both sides in each of the patients. Resting motor threshold, motor evoked potentials (MEP) amplitude at rest, MEP latency at rest and during contraction and silent period duration (SPD) were recorded and analyzed. Two groups of data were collected. Group 1 consisted of data from the operated side in all 30 patients. Group 2 consisted of data from the contralateral side and served as a control. RESULTS: Motor resting thresholds were similar in the two groups. Intragroup pre and post CEA comparisons showed no difference in the operated group and significant increased threshold after CEA on the non-operated side. There was no significant difference of TMS intensity for maximal MEP in either side before or after CEA. Latency at rest and during voluntary contraction and amplitude at rest showed no significant differences between or within groups' comparisons. In group 1 SPD showed a statistically significant increase after CEA as opposed to baseline. In group 2 SPD showed a non significant increase after CEA. CONCLUSION: In the absence of other MEP changes, our finding of prolonged SPD post-operatively suggests preferential influence of the inhibitory cortical circuits. The potential favorable effect of CEA in patients with hyperexcitability such as disabling spasticity after stroke should be further studied.

Stiff-person syndrome associated with oral isotretinoin treatment.

We describe a patient with severe nodulocystic acne who developed disabling muscle stiffness and painful superimposed spasms of the neck, back and upper limbs 10 days after the onset of oral isotretinoin treatment. The muscle hyperactivity condition, which revealed the clinical and electromyographic features of the stiff-person syndrome, gradually resolved 2 weeks after drug withdrawal.

Effect of carpal tunnel syndrome on median nerve proximal conduction estimated by F-waves.

Slowing of median nerve proximal motor conduction in patients with carpal tunnel syndrome (CTS) could be considered as an indicator of an additional proximal lesion (double crush syndrome). The effect of CTS on proximal conduction was assessed by comparing motor velocities calculated by F-waves obtained from muscles with the same root and nerve supply but different median branches, one emerging before the carpal tunnel (pronator quadratus muscle) and one passing through the tunnel (abductor pollicis brevis). Data were obtained from 26 patients with CTS and 21 age-matched healthy subjects. In the control group, the proximal (spinal cord and elbow) F-wave maximal velocity calculated when recording from abductor pollicis brevis (FCVmax-APB) was not different from the F-wave maximal velocity calculated when recording from pronator quadratus (FCVmax-PQ), while it was significantly different in the group of CTS patients, especially in patients with terminal motor latency greater than 4.5 ms (approximately 9% less, p = 0.001, Wilcoxon signed rank test). The study showed that median nerve proximal conduction velocity slowing in patients with CTS is restricted to the fibers that distally pass through the carpal tunnel and does not necessarily imply an additional proximal lesion. We suggest that comparison of FCVmax-APB and FCVmax-PQ could be useful when the question arises if a single (distal) or two (one distal, one proximal) lesions are responsible for a patient's symptoms.

Segmental myoclonus as the sole manifestation of a choroid plexus papilloma in the posterior fossa. Case report.

The authors describe the case of a 22-year-old woman with involuntary contractions of the sternocleidomastoid and trapezius muscles that resulted in turning movements of the head. The jerks displayed the clinical and neurophysiological characteristics of segmental myoclonus (SM) restricted to muscles supplied bilaterally by the first four cervical segments. Magnetic resonance imaging disclosed a tumor in the midline above the cisterna magna that was later histologically proven to be a choroid plexus papilloma. The patient's involuntary movements did not extend to other muscle groups or, in particular, to the palate, as one might have expected in the case of brainstem lesions. Myoclonus was the sole clinical manifestation of the tumor in this patient; other signs and symptoms invariably reported in other cases of posterior fossa papilloma, such as increased intracranial pressure or cranial nerve palsies, were absent. Release from suprasegmental control is suggested as a possible pathophysiological mechanism in this case of SM.

Sensorimotor polyneuropathy after a three-month oral acitretin therapy.

We report a patient with chronic plaque psoriasis who developed clinical and electrophysiologic features of polyneuropathy affecting motor and sensory fibers in upper and lower extremities after three months of treatment with oral acitretin. Drug withdrawal resulted in a complete clinical recovery and normalization of all electrophysiologic abnormalities within two months.

Motor nerve conduction velocities calculated by F tacheodispersion in patients with anterior horn diseases.

F tacheodispersion, a new neurophysiological technique based on F waves, was used to determine the motor nerve conduction velocities in 16 patients with motor neuron disease and 19 patients with sequelae following paralytic poliomyelitis. The findings were compared to two age-matched groups, each consisting of 20 healthy volunteers. In each subject the F wave maximal, minimal, mean conduction velocities and the difference between maximal and minimal velocities of the ulnar and peroneal nerves were calculated. M response distal latency, amplitude and conduction velocity were also measured. There was a statistical significant slowing of one or more of the F wave estimated velocities in the absence of M response abnormalities in 31.3% of nerves in motor neuron disease group and in 27.3% of nerves in the poliomyelitis group; between 6.3% and 37.5%, of the nerves studied showed a significant change in the difference between maximal and minimal conduction velocities. Our results favour the presence of changes of motor fibre conduction properties in some patients with anterior horn diseases.

Dynamic F wave study in patients suffering from peripheral arterial occlusive disease.

OBJECTIVE: To prospectively detect significant transient F wave abnormalities obtained after exercise in patients with peripheral arterial disease (PAD) and to assess the potential diagnostic sensitivity of dynamic F wave study in such a context. PATIENTS AND METHODS: A series of 40 electrical stimuli were delivered to the peroneal and the posterior tibial nerves of 25 patients with PAD in order to obtain F waves at rest and post-exercise. The following variables were estimated and the obtained pre- and post-exercise data were compared: F persistence, F wave latency, amplitude, duration and F chronodispersion. For each nerve studied, the minimum, average and maximum values were calculated. Conventional electrophysiological data were also collected pre- and post-exercise and the data obtained were also compared. Twenty-five healthy age-, gender- and height-matched individuals served as controls. RESULTS: No evidence of conventional nerve conduction abnormalities was recorded either pre- or post-exercise in the group of patients. As regards the peroneal nerve, the significantly reduced F wave persistence (P = 0.007) and maximum F wave amplitude post- as opposed to pre-exercise (P = 0.05)- were the main findings to emerge. The average (P = 0.017) and the minimum duration (P = 0.005) of tibial F waves were also significantly increased post- compared with pre-exercise. Insignificant differences were observed between pre- and post-exercise neurophysiological and F wave values in the group of controls. CONCLUSION: Given the observed absence of conventional neurophysiological abnormalities, the detection of dynamic F wave changes supports the view of an increased diagnostic sensitivity of this method in patients with mild PAD.

Clinical and electrophysiological features of peripheral neuropathy induced by administration of cisplatin plus paclitaxel-based chemotherapy.

The current prospective study sought to trace the incidence and severity of cisplatin plus paclitaxel (DDP+P)-induced neuropathy and to determine its clinical and electrophysiological pattern. Furthermore, it was attempted to describe its evolution by following up the course of peripheral neuropathy (PN) during chemotherapy as well as 3 months after its discontinuation. Thirteen adult patients scheduled to be treated with six courses of cumulative DDP+P-based regimens for a non-myeloid malignancy participated in this study. These patients were clinically and electrophysiologically monitored at baseline, during chemotherapy and 3 months after its discontinuation. The severity of PN was summarized by means of a modified PN score. Evidence of PN was disclosed in nine of the 13 patients (69.2%). The mean PN score for patients that manifested some grade of PN was 17.3 +/- 6.1 (range 9-28). All longitudinal comparisons concerning the motor conduction velocities (MCV) variables failed to reach significance. By contrast, comparisons of the mean changes at baseline and each of the follow-up studies revealed a significant decrease in all sensory action potentials examined. The follow-up evaluation performed 3 months after the discontinuation of chemotherapy showed that the DDP+P-induced neuropathy persists and progresses over time. Our results indicate that the majority of patients treated with a DDP+P-based regimen at full dose intensities would manifest an axonal, predominately sensory PN, of mild to moderate severity, which would persist for several months after the discontinuation of chemotherapy.