Graziano Arnetoli

Separate ipsilateral and contralateral corticospinal projections in congenital mirror movements: Neurophysiological evidence and significance for motor rehabilitation†

The neurophysiological hallmark of congenital mirror movements (MM) are fast‐conducting corticospinal projections from the hand area of one primary motor cortex to both sides of the spinal cord. It is still unclear whether the abnormal ipsilateral projection originates through branching fibres from the normal contralateral projection or constitutes a separate ipsilateral projection. To clarify this question, we used focal paired‐pulse transcranial magnetic stimulation to test task‐related modulation of short‐interval intracortical inhibition (SICI) in the abductor pollicis brevis (APB) muscles of a 15‐year‐old girl (Patient 1) and a 40‐year‐old woman (Patient 2) with congenital MM. In both patients, during intended unilateral APB contraction, SICI decreased markedly in the “task” APB but remained unchanged in the “mirror” APB when compared to muscle rest. In contrast, spinal excitability as tested with H reflexes increased similarly in the task and mirror flexor carpi radialis muscles. This dissociation of task‐related SICI modulation strongly supports the existence of a separate ipsilateral fast‐conducting corticospinal projection. In Patient 1, we tested the functional significance of this separate ipsilateral projection during 7 months of motor rehabilitation training, which was designed to facilitate unilateral finger movements. A marked reduction of MM was observed after training, suggesting that unwanted mirror activity in the ipsilateral pathway can be suppressed by learning.

Hyperammonemia and Valproate-Induced Alterations of the State of Consciousness

Sodium valproate was administered to 38 patients, admitted to our unit in the last 18 months, and chosen because they had: (1) poor control of their seizures; (2) therapeutic concentrations in their plasma of at least two major antiepileptic drugs. In 8 of them, a therapeutic dosage of VPA caused modifications of the state of consciousness ranging from coma to drowsiness and stupor. These patients also showed gastrointestinal disturbances, asterixis, ataxia, tremor and a worsening of EEG abnormalities. The side effects of the drug were constantly associated with increased concentration of blood ammonia. Better penetration of ammonia into the CNS of patients undergoing frequent seizures and possibly having imperfectly functioning biological barriers, could explain our observations. In view of the unusually high percentage of patients suffering from serious VPA side effects, it is probably advisable to carefully monitor ammonemia in the first few days of VPA therapy in every patient treated with multiple anticonvulsants.

MRI of spinal cord involvement in Behçet's disease : case report

Abstract MRI demonstrated well-defined areas of signal change and moderate contrast enhancement in the thoracic spinal cord of a patient with Behçets disease presenting with subacute myelopathy. The patient improved after intravenous steroids, and MRI 5 months later showed a normal spinal cord.

CINE-MR IMAGING OF AQUEDUCTAL CSF FLOW IN NORMAL PRESSURE HYDROCEPHALUS SYNDROME BEFORE AND AFTER CSF SHUNT

Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction.

Spinal intramedullary subependymomas : case report and review of the literature

A cervical spinal intramedullary subependymoma in a 53-year-old man is reported, and the relevant literature is reviewed. Spinal cord subependymomas seem to follow a benign course. Radiotherapy should not be administered to these patients. Magnetic resonance imaging, even with enhancement, is not able to distinguish between a subependymoma and the more common ependymoma.

Acute changes of blood ammonia may predict short‐term adverse effects of valproic acid

Valproic acid (VPA) was given to 24 epileptic patients who were already being treated with other antiepileptic drugs. A standardized loading dose of VPA was administered, and venous blood was sampled at 0,1,2,3, and 4 hours. Ammonia (NH,) was higher in patients who, during continuous therapy, complained of drowsiness (7 patients) than in those who were symptom-free (17 patients), although VPA plasma levels were similar in both groups. By measuring VPA-induced changes of blood NH3, content, it may be possible to identify patients at higher risk of obtundation when VPA is given chronically.

Eye movement abnormalities in anorexia nervosa

The aim of the present study is to investigate smooth pursuit eye movement and saccadic performance in anorexia nervosa during a restored weight period and to determine if functional links can be made between eye movement performance and clinical features. SPEM parameters were recorded for 28 female anorectic out-patients (DSM IV), who had a body weight loss of up to 20% of ideal body weight. Twenty-eight comparison subjects were also tested. Clinically, each patient was assessed using the Eating Disorder Inventory (EDI), the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Structured Interview for Personality Disorders (SCID II), the Symptom Checklist-90-Revised (SCL-90-R) and the Hamilton Scale for Depression (HRSD). The anorectic patients performed slightly worse than the comparison subjects on a number of SPEM measures. No relationship was found between SPEM impairment and a global severity index of psychopathology (SCL 90-R GSI) or depressive symptoms. Moreover, OCD symptoms and scores on some EDI scales (such as perfectionism) appear related to the severity of the eye movement alterations. The evidence of SPEM abnormalities in a subgroup of anorectic patients during the remitted state and the relationship of the abnormalities to obsessive-compulsive symptoms are discussed. Results are in agreement with the hypothesis regarding the persistence of neurophysiological as well as psychopathological traits of disorder in anorectic patients.

Electrophysiological Investigations of the Brainstem in the Vertebrobasilar Reversible Attacks

A total of 70 selected patients affected by reversible ischemic attacks in the vertebrobasilar system were studied. 50 patients presented transient ischemic attacks (TIA), while the other 20 patients suffered from 1-2 protracted transient ischemic attacks (PTIA). All patients underwent brainstem acoustic evoked potentials (BAEP) and electrooculography (EOG) 7-20 days from the last reversible ischemic attack, when all signs and symptoms completely disappeared. The combination of BAEP and EOG gave objective evidence of brainstem dysfunction in 61 out of 70 patients. BAEP resulted abnormal in 26 patients (16 TIA, 10 PTIA), EOG in 49 (36 TIA, 13 PTIA). Serial controls at 3, 6, and 12 months were conducted in 27 patients. 5 patients showed a normalization for BAEP and 7 for EOG 12 months after the first examination.

Conversion from thrice daily to twice daily administration of gabapentin (GBP) in partial epilepsy: analysis of clinical efficacy and plasma levels

Gabapentin has been administered in placebo-controlled studies with a thrice daily (T.I.D.) schedule, because of its short half-life. However, clinical efficacy does not seem strictly related to plasma levels: a twice daily (B.I.D.) schedule might therefore be possible. The aim of our study was to verify if the conversion from a T.I.D. to a B.I.D. regimen affected the efficacy and safety of gabapentin therapy. Out of 171 patients treated with add-on gabapentin, we selected 29 stable responders, who were followed for three months with a T.I.D. schedule and then switched to B.I.D. regimen for further three months. Seizure number, side-effects and trough plasma levels of gabapentin were collected during both periods. Gabapentin mean dose was 2117.2 mg/day. Mean number of seizures/months was: 4.2 at baseline, 1.0 during the T.I.D., and 0.9 during the B.I.D. period. Mean trough plasma level of gabapentin was 5.9 microgram/ml during the T.I.D. and 5.2 microgram/ml during the B.I.D. period. Twelve side-effects were reported by 11 patients during the T.I.D. and 6 by 5 patients during the B.I.D. period., sedation and vertigo were the most frequent in both. Results of our study suggest that gabapentin can be administered safely and effectively either with a T.I.D. and a B.I.D. regimen.

Combined Partial Temporal and Secondary Generalized Status Epilepticus

A right-handed 32-year-old woman had recurrent combined partial temporal and secondary generalized epileptic states almost constantly related to menstruations. During such more or less prolonged episodes sometimes the patient presented right adversive attacks with short postictal dysphasia. The catamenial status epilepticus observed in this cas was manifested in two clear-cut behavioral phases. The first phase was characterized by frequently recurrent left temporal epileptiform discharges without tendency to diffusion, progressively more prolonged and pseudorhythmic associated with a signalized feeling of intense fear without apparent impairment of consciousness or speech disturbances. The electroclinical features of the first phase suggest a depth origin of the paroxysms, probably due to a primary epileptogenic focus in the left amygdaloid-hippocampal complex. In the second phase the left temporal focal semirhythmic discharges associated with fear bouts became more frequent and prolonged and began to be followed by long-lasting generalized discharges resulting in a trance-like state with severe impairment of consciousness. The diffuse paroxysmal activity regularly preceded by the left temporal focal discharges was interpreted as a form of secondary bilateral synchrony constantly triggered from a focal pacemaker represented by the primary epileptogenic focus. During the very short transient periods of sudden cessation of the epileptiform activity the patient returned immediately to an apparent normal mental state. Good correlation could be established between different seizure patterns and predominant clinical signs. Intravenous diazepam rapidly decreased and then completely stopped the catamenial status epilepticus. Some problems related to the classification of these rare epileptic events are discussed.