Seizures triggered by blinking when beginning to speak.

A patient had seizures triggered by spontaneous blinking associated with the act of beginning to speak. Diffuse paroxysmal discharges in the EEG appeared when the patient was blinking in darkness or in bright light. Closing the eyes voluntarily, on command, or as a reflex reaction produced this response very infrequently. During intermittent photic stimulation the epileptic discharges were accompanied by myoclonic jerks. The act of beginning to speak was linked with spontaneous blinking and EEG changes and was accompanied consistently by seizures. These were characterized by a peculiar stuttering and an absencelike impairment of consciousness. Seizures have been controlled well using clonazepam and valproic acid.

The effect of amantadine on arousal and EEG patterns in Creutzfeldt-Jakob disease.

In recent years, Creutzfeldt-Jakob disease (CJD) has been supposed to be of viral origin, and amantadine hydrochloride has been suggested as therapy because of its proved antiviral action. We studied nine patients with CJD (confirmed at autopsy in seven). Four were treated with amantadine hydrochloride, in dosages ranging from 3.5 to 15 mg/kg/day for an average period of 32 days. The clinical evolution of their disease was compared with that in five patients receiving only supportive maintenance therapy. The length of survival from the onset of clinical care did not differ significantly between the two groups. Nevertheless, a transient improvement in wakefulness and mentation was observed in three patients treated with amantadine, and EEG changes were observed in two, consisting above all of a reduction in the slow-wave activity and the periodic discharges (PDs). Amantadine administered intravenously did not induce any short-term changes in the PDs or the cyclic alternating pattern.

The cyclic alternating pattern as a physiologic component of normal NREM sleep.

The cyclic alternating pattern (CAP) is a long-lasting periodic activity consisting of two alternate electroencephalogram (EEG) patterns. This variation in EEG is closely related to fluctuations in the level of arousal that characterize two different functional states in the arousal control mechanism. We studied 20 sleep records of 10 healthy subjects to see if CAP appears under physiologic conditions. During NREM sleep, CAP corresponded to a periodic succession of spontaneous phasic phenomena recurring within every stage, i.e., intermittent alpha rhythm, K-complex sequences, and reactive slow wave sequences. The following analyses were performed. Each EEG specific alternating pattern, defined as a cycle, was subdivided into two phases depending on the arousal response to stimulation. Average cycle length, average duration of each phase, and average ratio phase/cycle were calculated. CAP rate defined as (CAP time/Sleep time) was calculated for total sleep time (TST), (Cap time/TST); for NREM sleep, (CAP time/Total NREM); and for each NREM sleep stage. CAP is the EEG translation of the reorganization of the sleeping brain challenged by the modification of environmental conditions.

Precocious loss of physiological sleep in a case of Creutzfeldt Jakob disease: a serial polygraphic study.

Creutzfeldt-Jakob disease (CJD) is a prion-related subacute encephalopathy producing widespread neuronal degeneration and spongiform pathological changes, especially in the neocortex. Progressive dementia, motor signs and electroencephalographic (EEG) alterations characterize the full stage of the disease. A series of eight 24-hour polygraphic recordings were carried out in the last 3 months of life of a 68-year-old female patient affected by CJD that was confirmed neuropathologically. Genetic classification demonstrated this patient to have a sporadic form of the disease. The polygraphic recordings demonstrated three types of EEG findings, as follows: 1) sustained pseudoperiodic discharges (SPD), characterized by long-lasting diffuse sequences of slow sharp waves or di- or triphasic slow waves recurring at 0.5- to 1.5-second intervals; 2) discontinuous pseudoperiodic discharges (DPD), consisting of runs of pseudoperiodic discharges (PD)(phase A) cyclically replaced at about 1-minute intervals with semi-rhythmic theta-delta activities (phase B); 3) non-rapid eye movement (NREM) sleep-like pattern, with dominant 0.5- to 4-Hz activities, less rhythmic than the EEG of phase B. Only these three EEG patterns occurred spontaneously during the repeated polygraphic sessions. The NREM sleep-like pattern was found only in the first recording, whereas the following polygraphic sessions were occupied exclusively by SPD or by a DPD pattern. SPD was associated with either a relatively high level of vigilance (along the first three recordings) or a state of alert-appearing silent immobility (following the fourth recording). During DPD, the patient was unable to accomplish any voluntary movement and fluctuated between levels of greater arousal (phase A) and lesser arousal (phase B). Just as in stage 2 coma, the fluctuations between phases A and B of DPD were synchronous with phasic modifications of muscle activity and neurovegetative functions. In particular, reinforcement of muscle tone and myoclonic spasms coincided with phase A, whereas heart rate deceleration and respiratory pauses or decrease in flow were synchronous with phase B. As EEG evolved toward the disappearance of DPD and finally to flatness, the phase-locked coordination among arousal, somatic and vegetative activities was progressively impaired and was replaced with an uncontrolled exaggeration of cardiorespiratory activity. The genetic, neuropathological and polysomnographic differences between CJD and another prion disease, fatal familial insomnia, are discussed.

Diffuse thalamic degeneration in fatal familial insomnia. A morphometric study.

A morphometric investigation disclosed most thalamic nuclei severely degenerated in two patients with fatal familial insomnia. Associative and motor nuclei lost 90% neurons, and limbic-paralimbic, intralaminar and reticular nuclei lost 60%. These findings point to the disorganization of most thalamic circuits as a condition necessary for the sleep-wake rhythm being affected.

Masseteric repetitive nerve stimulation in the diagnosis of myasthenia gravis.

OBJECTIVE: (1) to develop a method for masseteric repetitive nerve stimulation (RNS) and to obtain normative data for amplitude and area decrement of the muscle (M) response. (2) To investigate myasthenia gravis (MG) patients with masseteric RNS. Masticatory muscles are frequently affected in MG, but no RNS test is available to investigate this district. METHODS: Fifteen healthy subjects and 17 MG patients were examined. The masseteric nerve was stimulated by a monopolar needle (cathode), inserted between the mandibular incisure and the zygomatic arch, and a surface electrode (anode), on the contralateral cheek. Masseteric M response was recorded using surface electrodes on the muscle belly and below the mandibular angle. Stimuli were delivered at 3 Hz in trains of 9, at rest and after isometric effort. RESULTS: Normal subjects: mean amplitude decrement was 0.3+/-1.2% at rest, and 1.9+/-1.3% after isometric effort. PATIENTS: 15 patients (88%) were positive on masseteric RNS; in 3 of these it was the only positive RNS test. The extent of decrement observed in masseter muscle was significantly greater than in trapezius muscle. CONCLUSIONS: Masseteric RNS is a simple and well-tolerated procedure; it offers a new possibility in testing the cranial muscles in disorders of neuromuscular transmission.

Motor-evoked potentials in masseter muscle by electrical and magnetic stimulation in intact alert man.

The electromyographic responses of the masseter after different types of transcranial stimulation were recorded with surface and needle electrodes. Magnetic stimulation at 4 cm lateral to the vertex on the biauricular line elicited MEPs in the contralateral masseter (latency 6.9 ms) due to activation of motor cortex or adjacent elements along the cortico-nuclear pathway. The ipsilateral responses to the same stimuli and to more lateral ones had shorter latencies and were ascribed to direct stimulation of the trigeminal nerve, probably its intracisternal portion. This was also the probable origin of the ipsilateral MEPs after both anodic and cathodic bipolar electrical stimulation at 7 and 11 cm lateral to the vertex on the biauricular line.

Post-anoxic theta and alpha pattern coma.

Theta pattern coma is a rare EEG finding, described in the course of post-anoxic or post-traumatic coma and interpreted as a "malignant" variant of alpha pattern coma. A case of isolated theta pattern coma, followed by alpha pattern coma is reported. Short temporal succession of such patterns would seem to confirm the hypothesis of a close relationship between them. Possible physiological mechanisms involved in the generation of the patterns are discussed.

Spindle coma and alternating pattern in the course of measles encephalitis.

Acute disseminated encephalomyelitis (ADEM) is a well known complication of measles infection. Electroencephalographic abnormalities may occur frequently, in the form of moderate to severe diffuse high voltage theta-delta activity. We report a case of measles encephalitis with rapid benign outcome, that showed peculiar EEG features both of a "spindle coma" pattern and of an "alternating pattern." Possible physiological explanations of the EEG findings are discussed.

Triphasic waves associated with acute naproxen overdose: a case report.

Triphasic waves (TWs) can be recorded on EEG in the course of several metabolic disorders, mainly hepatic encephalopathy. A case of acute encephalopathy due to naproxen intoxication is reported, in the course of which diffuse, bilateral and symmetrical TWs were recorded. Biochemical mechanisms that might determine both a complex encephalopathy and TWs are discussed.

Flunarizine as add-on therapy in epilepsy. Crossover study vs placebo.

The anticonvulsive effect of flunarizine was studied in a multicenter trial, by means of a randomized, double-blind, single crossover design. The subjects who entered the study were 51 males and 39 females, aged 15 to 73 years. They were epileptic patients who suffered from at least two generalized seizures per month or more than 4 partial seizures per month. The patients were already being treated with major antiepileptic drugs. Flunarizine was administered in a single evening dose of 10 mg/die in patients who weighed less than 70 kg and of 15 mg/die in patients who weighed more 70 kg. Our results show that flunarizine, given as add-on therapy, produced a slight but significant decrease in the number of monthly seizures at the end of a 3-month period, while placebo did not significantly change the seizures frequency.

Partial seizures and migraine.

Epilepsy and migraine, despite some common features, have quite different pathophysiological mechanisms. Studies carried out on large population samples have shown that the relationships between migraine and epilepsy may be of the following type: associated attacks, with migraine and seizures occurring quite independently of one another; combined attacks, with the two types of attacks succeeding one another in time; basilar artery migraine with seizures and marked EEG abnormalities; benign epilepsies with occipital discharges, migraine and intercalated seizures. We report four cases of particular interest.

The masseteric inhibitory reflex in the diagnosis of multiple sclerosis.

In order to evaluate the reliability of the masseteric inhibitory reflex (MIR) as a screening method in the diagnosis of multiple sclerosis (MS), a series of 41 consecutive patients affected by clinically defined, long-duration forms (mean duration 10.9 years) of the disease was examined. In all cases magnetic resonance imaging and CSF isoelectrofocusing confirmed the diagnosis. Sensitivity of MIR, Blink Reflex and BAEPs were compared. Statistical analysis of data suggested the following considerations: 1) a significant concordance was found between MIR and the other neurophysiological tests performed (MIR vs. BAEPs in 78.4% of cases, p < 0.001; MIR vs. blink reflex in 68.3%, p < 0.02). 2) The S1 early component of MIR is a more reliable indicator than S2 late component. 3) In detecting brainstem lesions the sensitivity of MIR equaled that of the other neurophysiological tests. 4) Poor localizing concordance between neurophysiological tests and neuroimaging was found in our series. A possible utilization of MIR, as a part of a multimodal neurophysiological approach, even in patients affected by possible or probable MS is suggested.

Presurgical electrophysiological findings in acoustic nerve tumours.

The clinical involvement of the facial nerve is a rare finding among the initial symptoms of acoustic neurinomas. However, compression of the facial nerve is a common intraoperative finding. Blink reflex was recorded in 20 patients affected by cerebellar-pontine angle tumor confirmed at surgery. Recordings were also made of the M-response of the facial nerve from the naso-labial folds. In 6 cases jaw reflex was also recorded. In summary, these electrophysiological studies revealed a facial nerve damage in 13 and a trigeminal nerve dysfunction in 2 out of 18 clinically unaffected patients. The combined study of the 3 tests proved to be useful when the blink reflex showed an isolated R1 delay, that is, in cases in which the level of damage along the trigemino-facial reflex arc cannot be defined by the recording of the blink reflex alone.

On the cause of tendon areflexia in the Holmes-Adie syndrome.

A case of Holmes-Adie syndrome was studied clinically and electrophysiologically. A total loss of tendon reflexes was observed in upper and lower limbs. The main electrophysiological finding was a marked increase of the central conduction time after stimulation of peroneal and tibial nerves. Motor evoked potentials in soleus muscle after transcranial magnetic stimulation showed normal threshold and latencies. We suggest that tendon areflexia could be a consequence of a dysfunction of somatosensory large diameter afferent fibres at the spinal level.

Magnetic motor evoked potentials (MEPs) in masseter muscles.

Electromyographic responses of the masseter muscles and orbicularis oris muscles following transcranial magnetic stimulations were recorded with surface and needle electrodes. MEPs in masseter muscles (latency 6.9 +/- 0.71 ms, mean +/- SD) due to activation of controlateral cortico-nuclear connections were evoked by magnetic stimulations at 4 cm laterally to the vertex on the biauricular line. These MEPs were followed bilaterally by a silent period lasting about 20 ms and, less constantly, by a later silent period lasting up to 80 ms. The ipsilateral responses to the same stimuli presented shorter latencies and higher amplitudes and they were ascribed to direct stimulation of the trigeminal nerve, probably its intracisternal portion. Ipsilateral masseter "cortical" MEPs could be elicited only by a lower output setting (70% of the maximum output) of the stimulator. Orbicularis oris MEPs were polyphasic and dispersed with latencies ranging from 7 to 11 ms. In patients with hemispheric or capsular ischemic lesions "cortical" MEPs were absent when stimulating the affected hemisphere and present when stimulating the unaffected one. We suggest that the direct corticomotoneuronal projections for the masseter are mainly crossed.

[Magnetic stimulation of the scalp: the responses of the masseter muscles. I]. / Stimolazione magnetica allo scalpo: risposte nei masseteri. Parte I.

Magnetic stimulation of nervous elements is a new neurophysiological technique. It easily succeeds in stimulating the brain motor cortex. We applied this technique to the trigeminal motor system, recording responses in masseter muscles. The magnetic stimulations at 4 cm laterally to the vertex on the biauricular line elicited responses in the contralateral masseter due to activation of motor cortex or adjacent elements along the cortico-nuclear pathway. The ipsilateral responses to the same stimuli and to more lateral ones presented shorter latencies and they were ascribed to direct stimulation of the trigeminal nerve, probably its intracisternal portion. The latency values were 6.9 +/- 0.71 ms and 3.6 +/- 0.3 ms respectively.

[Magnetic stimulation of the scalp: the responses of the masseter muscles. II]. / Stimolazione magnetica allo scalpo: risposte nei masseteri. Parte II.

Magnetic stimulation of nervous elements is a new technique of investigation in intact alert man. Electromyographic responses of the masseter muscles were recorded in normal volunteers and in two patients with hemispheric or capsular lesions, both by surface and needle electrodes. In the patients "cortical" responses were absent when stimulating the affected hemisphere and present when stimulating the unaffected one. These findings suggest that the direct facilitating cortico-nuclear projections for the masseter muscle are mainly crossed. Nevertheless the presence of clear ipsilateral responses after stimulation of the unaffected hemisphere demonstrates the existence of uncrossed projections; in fact only the ipsilateral motor cortex can be the site of origin of the responses in these patients.

[Masseteric responses following electrical stimulation of the scalp]. / Risposte masseterine seguenti stimolazioni elettriche allo scalpo.

Electromyographic responses of the masseter muscles following electric transcranial stimulations by a conventional constant current stimulator were recorded with surface and needle electrodes. Ipsilateral motor evoked responses following both anodic and cathodic bipolar electrical stimulations performed at 7 and 11 cm laterally to the vertex on the biauricular line were recorded, with latencies ranging from 2 to 3.6 ms. Contralateral responses were not elicited. The ipsilateral responses to stimuli were ascribed to direct stimulation of the trigeminal nerve, probably its intracisternal portion.