Mucoepidermoid carcinoma of the retromolar region: case report / Carcinoma mucoepidermoide em região retromolar: relato de caso

ABSTRACT The present study aimed to report a case of mucoepidermoid carcinoma (MEC), focusing on its clinical-pathological characteristics. At intraoral clinical examination, a nodular lesion was observed in the right pterygomandibular raphe region, with three years of evolution. An incisional biopsy was performed, and the diagnostic hypotheses of salivary gland injury and sialadenitis were considered. Histopathologically, a malignant neoplastic process characterized by the proliferation of epidermoid, intermediate and mucosal cells was observed. The histopathological diagnosis of MEC was emitted. The present case praises the importance of early diagnosis and correct management of this disease, providing a better prognosis for these patients.

RESUMEN Reportamos un caso de carcinoma mucoepidermoide (CME) con enfoque en sus rasgos clinicopatológicos. En la exploración clínica intraoral, se observó una lesión de aspecto nodular en región del rafe pterigomandibular derecho, con tiempo de evolución de tres años. Se realizó una biopsia por incisión, considerándose las hipótesis diagnósticas de lesión de glándula salival y sialadenitis. Histopatológicamente, se observó un proceso neoplásico maligno caracterizado por la proliferación de células epidermoides, intermedias y mucosas. El diagnóstico histopatológico fue de CME. El presente caso destaca la importancia del diagnóstico temprano y del manejo correcto de esa enfermedad, ofreciendo un mejor pronóstico para los pacientes portadores de CME.

RESUMO Relatamos um caso de carcinoma mucoepidermoide (CME) com enfoque em suas características clinicopatológicas. No exame clínico intraoral, observou-se lesão de aspecto nodular em região de rafe pterigomandibular direita, com tempo de evolução de três anos. Biópsia incisional foi realizada, e as hipóteses diagnósticas de lesão de glândula salivar e sialadenite foram consideradas. Histopatologicamente, observou-se um processo neoplásico maligno caracterizado pela proliferação de células epidermoides, intermediárias e mucosas. O diagnóstico histopatológico de CME foi emitido. O presente caso enaltece a importância do diagnóstico precoce e do correto manejo dessa patologia, proporcionado um melhor prognóstico para os pacientes portadores de CME.

Tetrabenazine improves levodopa-induced peak-dose dyskinesias in patients with Parkinson's disease.

Since levodopa-induced peak dyskinesias (LIDs) may reflect, in part, a disproportionate phasic release of dopamine from synaptic vesicles, we examined the ability of the vesicular depletor tetrabenazine (TBZ) to reduce LIDs in 10 dyskinetic advanced Parkinson's disease (PD) patients. After basal evaluation, the patients received, through a slow titration, oral TBZ twice a day for six weeks (up to 50 mg daily) before being re-assessed after a challenge with levodopa. The primary outcome measure was the change in the Unified Parkinson's Disease Rating Scale (UPDRS) dyskinesia score (items 32 to 34). TBZ was well tolerated. A clear treatment effect on LIDs emerged (up to 45%, p<0.05). In two patients a little worsening of motor performance necessitated an increase of the antiparkinsonian therapy, which did not worsen peak-dose LIDs. The patients experienced a clear benefit in terms of their quality of life. In this open-label pilot study, orally administered TBZ resulted in objective and subjective improvements in LIDs. Larger pharmacological studies are in progress.

Multiple myeloma and paget disease with abnormal skull lesions and intracranial hypertension.

We report a 73 years old man with a diagnosis of Paget Disease (PD) and symptomatic Multiple Myeloma (MM). Coexistence of MM and PD has rarely been described. PD mimics many of the features of bone destructive process in MM, making differential diagnosis more complicated. In addition, the presence of serious muscolo-skeletal and metabolic complications in both diseases makes management of patients difficult, worsening the prognosis.The comparison of these two diseases has led to the characterization of a common molecular mechanism represented by the receptor activator of nuclear factor-kB ligand (RANKL)/Osteoprotegerin signaling pathway. The improved comprehension of these mechanisms led to the development of new pharmacologic agents (bisphosphonates, cytokines inhibitors) effective for the treatment of these bone diseases.

Peripheral arterial tone as an on-line measure of load in a simulated flight task.

Variations in continuous and discrete flight demands were investigated in a simulated flight mission measuring peripheral arterial tone (PAT) from the tip of the finger. A total of 12 participants performed a computer-simulated agricultural flight task. They were required to fly over a specific lane of a simulated corn field (continuous task) and change lanes in response to flags, which appeared at varying intervals (discrete task). The difficulty of the flight task was manipulated by varying the airplane control (single- vs. dual-axis control), while the difficulty of the discrete task was manipulated by varying the amount of lateral change signalled by the flag. PAT amplitude was lower in the difficult level of the continuous task and was further attenuated following the appearance of the flag only when a change in the flight position was required. These results suggest the potential utility of PAT as an on-line measure of the joint continuous and discrete demands of a flight mission.

Acute vs chronic effects of l-dopa on bladder function in patients with mild Parkinson disease.

OBJECTIVE: To compare acute and chronic effects of l-dopa on bladder function in levodopa-naive Parkinson disease (PD) patients who had urinary urgency. METHODS: We evaluated 26 l-dopa-naive PD patients at a university-based PD center with a first urodynamic session with a double examination: in the off treatment condition and 1 hour after acute challenge with carbidopa/l-dopa 50/200 mg; then, a chronic l-dopa monotherapy was administered (mean dose 300 +/- 150 mg). Two months later, patients underwent a second urodynamic session with a single evaluation 1 hour after the acute carbidopa/l-dopa challenge. RESULTS: The first acute l-dopa challenge significantly worsened bladder overactivity (neurogenic overactive detrusor contractions threshold [NDOC-t; 32% of worsening] and bladder capacity [BC; 22% of worsening]); on the contrary, l-dopa challenge during chronic administration ameliorated the first sensation of bladder filling (FS; 120% of improvement), NDOCT-t (93% improvement), and BC (33% of improvement) vs the values obtained with acute administration. An 86% significant improvement of FS in comparison with the basal value was observed. CONCLUSIONS: The acute and chronic l-dopa effects may be due to the different synaptic concentrations or to the activation of postsynaptic mechanisms obtained by chronic administration.

Shifting attention between objects.

Experiment 1 used a modified spatial cueing paradigm that was introduced by Egly et al. [J. Exp. Psychol. Gen. 123 (1994) 161] to investigate the cost incurred in shifting attention within an object as opposed to shifting attention between objects. Subjects were presented with two outline rectangles and had to detect a target (a luminance increment) that could appear in the cued location (valid trials), in an uncued location inside the cued rectangle (inside-invalid trials), or in an uncued location inside the uncued rectangle (outside-invalid trials). Valid trials were faster than invalid trials, and inside-invalid trials were faster than outside-invalid trials. In Experiment 2, the two rectangles were joined to form a unitary object. Here, no difference was found between outside-invalid trials and inside-invalid trials. Experiment 3 showed that the delayed response on outside-invalid trials in Experiment 1 was not due to attention needing to cross the figural borders in order to re-orient to the uncued rectangle. The results were interpreted as showing that an extra cost is incurred for shifting attention between different objects.

Ipsilateral activation of the unaffected motor cortex in patients with hemiparetic stroke.

BACKGROUND AND PURPOSE: Recent research has shown that following stroke patients can display ipsilateral activity reflecting a functional link between the undamaged hemisphere and the affected upper limb on the same side of the body. In the present study the capacity for ipsilateral activation is documented during recovery by using transcranial magnetic stimulation (TMS) and transcranial Doppler (TCD). METHODS: Fourteen patients affected by hemispheric stroke were examined with TMS and TCD within 48 h of onset, and again 6 months later. Neurological signs were scored with reference to the NIHSS, and patients executed a thumb to finger opposition task so as to further estimate the motor deficit. Twenty healthy volunteers represented the control population. RESULTS: (1) Both TMS and TCD yielded homogeneous results showing ipsilateral activity between affected hands and undamaged hemispheres. On stimulating the motor cortex 3 cm anterior and 3 cm lateral to Cz, a scalp site remote from the primary motor area, ipsilateral motor evoked potentials (iMEPs) from hand muscles were found in recovered patients. (2) In 8 controls iMEPs with smaller amplitudes than patients could be obtained by stimulating only the left hemisphere. (3) TCD revealed increased blood flow velocity in the ipsilateral MCA by activating the recovering hand (10.5+/-3.3%; P<0.001). CONCLUSION: TMS reveals a specific area in the motor cortex from which ipsilateral MEPs can be elicited and both TMS and TCD indicate that an ipsilateral corticospinal tract can be accessible in some adult controls or becomes unmasked after cerebral damage.

Pharmacologic reversal of cortical hyperexcitability in patients with ALS.

OBJECTIVE: To reverse the profile of abnormal intracortical excitability in patients with ALS by administering drugs that promote GABAergic transmission. BACKGROUND: Transcranial magnetic stimulation (TMS) has revealed abnormalities of cortical inhibition in ALS, a reduction of the silent period, and the absence of intracortical inhibition normally occurring in response to paired TMS. Impaired inhibitory transmission could play a role in the physiopathology of this illness. METHODS: Using paired TMS with conditioning stimuli from 1-to-6-msec-interstimulus intervals, we investigated 16 patients with ALS. The protocol included: (1) the "drug-free" profile of paired TMS; (2) paired TMS 30 minutes after the intake of diazepam (3.5 mg); (3) paired TMS after 3 weeks' treatment with gabapentin (GBP) (600 mg/day) or riluzole (50 mg/twice a day). RESULTS: Intracortical inhibition is lost in patients with ALS, and this abnormal profile is reversed by diazepam or sustained treatment with GBP. We also noted that motor-evoked potential amplitudes to single stimuli increased (p<0.01) after diazepam and GBP. CONCLUSIONS: The demonstration of pharmacologic reversal of hyperexcitability in patients with ALS makes a potentially significant contribution toward understanding the pathophysiology of a disease that has so far eluded an effective cure.

Quantitative analysis of the pendulum test: application to multiple sclerosis patients treated with botulinum toxin.

The aim of this study was to develop quantitative analytical methods in the application of the pendulum test to both normal and spastic subjects. The lower leg was released by a torque motor from different starting positions. The resulting changes in the knee angle were fitted by means of a time-varying model. Stiffness and viscosity coefficients were derived for each half-cycle oscillation in both flexion and extension, and for all knee starting positions. This method was applied to the assessment of the effects of Botulinum toxin A (BTX) in progressive multiple sclerosis patients in a follow-up study. About half of the patients showed a significant decrement in stiffness and viscosity coefficients.

The effect of benzodiazepines and flumazenil on motor cortical excitability in the human brain.

In the present study, the effects of benzodiazepines (diazepam) were evaluated in terms of cortical excitability changes, as tested with transcranial magnetic simulation (TMS). In particular, analyzed were drug-induced changes regarding two selected parameters of TMS: (1) the cortical excitability threshold and (2) the silent period duration (SP). For this purpose, we evaluated the effects of long-term therapy with diazepam in the patients affected by anxiety disorders and the changes induced by single oral doses of diazepam in both healthy controls and patients. In addition, we tested cortical excitability changes in two 'extreme conditions' where a considerable concentration of serum benzodiazepine-like activity was reached, as represented by diazepam overdose and idiopathic recurrent stupor (IRS). In both groups of patients, a significant increment of motor threshold was found, while in the overdose patients, the SP was also increased. The administration of flumazenil in these two conditions was followed by a prompt reversal effect, consisting of a return to normal cortical excitability parameters. The long-term usage of diazepam in patients with anxiety disorders is associated with significantly increased threshold; the increased value of these parameters was temporarily further enhanced by the administration of a single oral dose of diazepam, which, in normal control subjects, is not associated with changes of cortical excitability. The results of this study reveal that different physio-pathological conditions induced by the influence of benzodiazepine and its antagonist are reflected in excitability changes which attest to the involvement and modification of cortical GABAergic activity.

The treatment of severe forms of myasthenia gravis.

In this study we introduced and tested the clinical efficacy of a combined treatment based on the association of plasma exchange (PE) with high daily doses of prednisone in 18 patients with severe forms of myasthenia gravis (MG). A myasthenic score based on strength and resistance was evaluated in each patient in basal condition and during the treatment. The study design included 5 sessions of PE, performed within a period of 15 days, 1 session every 3 days, associated with administration of oral prednisone (1 mg/kg of body weight), which began at the same time as the first session and was continued following a daily schedule for at least three months. A significant improvement was obtained from the start of the therapy, with a reduction of the myasthenic score from 26.56 to 11.44 by day 10 and with further reduction after PE interruption. An early improvement, recorded within 24-48 hours of the beginning of the study design, was observed in 11/18. The administration of steroid therapy was never followed by a worsening of myasthenic symptoms (as reported when it is administered in the absence of concomitant PE). No recurrence of symptoms was reported after 29 months' follow-up. This type of therapeutic association was generally well tolerated and no unwanted side effects were observed. According to our results we can conclude that medium-high doses of oral prednisone in simultaneous association with PE lead to a successful control of severe forms of MG and may be considered a valid therapeutic strategy.

Ipsilateral motor activation in patients with cerebral gliomas.

OBJECTIVE: The aim of this study is to provide neurophysiologic evidence of ipsilateral hemispheric activation in patients affected by intracerebral gliomas via the use of transcranial magnetic stimulation. BACKGROUND: The mechanisms involved in such ipsilateral activation have yet to be established, but they may involve preexisting routes that either are suppressed or undetected in the normal brain. Ipsilateral pathways may act in reserve, activated by the impairment of contralateral control. This hypothesis is suggested by the fact that the considerable size of the tumors in our patients is not matched by a proportionate loss of motor performance in the limbs contralateral to the affected hemisphere. However, it remains possible that ipsilateral motor-evoked potentials (iMEPs) may reflect reorganizational changes without significant functional effects. METHODS: The effects of such activation were investigated using both focal and nonfocal coils stimulating cortical motor areas, with MEPs recorded from both left and right thenar muscles. Fifteen healthy control subjects and seven patients were examined. RESULTS: iMEPs were generally absent in normal subjects, but in contrast they were obtained in the patients by stimulating the healthy hemisphere using both round and figure-of-eight coils. Distinct from contralateral MEPs, iMEPs are obtained with higher thresholds (range, 60 to 80% of stimulator output) and display longer latencies (20.9 msec versus 19.4 msec). CONCLUSIONS: Taken in conjunction with recent research using functional imaging brain exploration and a variety of clinical, anatomic, and neurophysiologic studies, our results reflect a growing awareness of ipsilateral motor control and its potential compensatory role when contralateral routes are damaged.

Plasmapheresis in severe forms of myasthenia gravis.

In this study we introduce a new combination treatment of plasma exchange (PE) and high daily doses of prednisone for severe forms of myasthenia gravis (MG). The clinical efficacy of the combined therapy has been tested in 18 patients suffering from severe forms of MG. The protocol included 5 sessions of PE, performed in a range of 15 days, 1 session every 3 days, with concurrent administration of oral prednisone (1 mg/kg of body weight), starting at the first session of PE and given daily for at least 3 months. At the end of the entire cycle of PE, almost complete recovery (more than 90% of the initial clinical score) was obtained in 8 of 18 patients while an improvement between 60 and 90% of the initial score was achieved in 9 of 18 patients. An early improvement was noted 24 h after the beginning of plasmapheresis in 11 of 18 patients. No recurrence of symptoms was reported after 36 months of follow-up for 17 patients. The administration of steroid therapy was never followed by an early exacerbation of myasthenic symptoms as reported when it is administered in the absence of concomitant PE. According to our results, we can conclude that high doses of oral prednisone therapy in simultaneous association with PE lead to successful control of severe forms of MG, significantly superior to the therapeutic strategies until now adopted and reported in literature.

Delayed focal involvement of upper motor neurons in the Madras pattern of motor neuron disease.

We report the case of a young man from the south of India, initially presenting the typical signs of benign monomelic amyotrophy (BMA) in the left upper limb. After several years, the involvement of other limbs and the appearance of bulbar signs suggested the possible diagnosis of the Madras pattern of motor neuron disease (MMND). Serial motor evoked potential (MEP) recordings allowed detection of the onset of a focal involvement of upper motor neurons (UMN) controlling innervation in the originally amyotrophic limb. Therefore, serial MEP recordings can be useful for the early detection of sub-clinical UMN damage in motor neuron disease presenting with pure lower motor neuron (LMN) signs.

The Simon effect occurs relative to the direction of an attention shift.

We investigated whether the Simon effect depends on the orienting of attention. In Experiment 1, participants were required to execute left-right discriminative responses to 2 patterns that were presented to the left or right of fixation. The 2 patterns were similar, and the discrimination was difficult. A letter at fixation signaled whether the current trial was a catch trial. The results showed a reversal of the Simon effect. That is, spatially noncorresponding responses were faster than spatially corresponding responses. In Experiment 2, the discrimination of the relevant stimulus attribute was easy. In Experiment 3, the discrimination of the relevant stimulus attribute was difficult, but the stimulus exposure time was long. In either experiment, the regular Simon effect was reinstated. In Experiment 4, the letter that signaled a catch trial appeared to the left or right of the imperative stimulus. The Simon effect occurred relative to the position of the letter.

Paroxysmal staring and masticatory automatisms during postural hypotension in a patient with multiple system atrophy.

PURPOSE: We studied a 51-year-old man with multiple system atrophy and autonomic insufficiency. He had repeated episodes of loss of contact, staring, and masticatory automatisms. METHODS: Blood pressure during these events documented a systolic pressure of 60 mm Hg. Cardiovascular reflex tests provided evidence of autonomic failure. Head computed tomography (CT) revealed moderate, diffuse cortical and cerebellar atrophy. RESULTS: These events were strictly related to blood pressure decreases and could be reproduced consistently by having the patient sit up after a meal. Ictal polygraphic recordings showed EEG changes consistent with anoxia, preceded by sudden hypotension with fixed heart rate. CONCLUSIONS: Cerebral anoxia during a syncopal attack may therefore precipitate transient, sudden neurologic dysfunction that closely mimics complex partial seizures. Masticatory automatisms may represent a release phenomenon resulting from inactivation of neocortical structures by cerebral anoxia or reticular disconnection.