Peripheral neuropathy and visual evoked potential changes in workers exposed to n-hexane.

The aim of this study was to evaluate patients who had peripheral neuropathy and changes to their visual evoked responses resulting from exposure to n-hexane. Eighteen patients with acute or subacute neuropathy, who were working in a shoe factory, were investigated clinically and electrophysiologically. These evaluations were then repeated 9 months to 12 months after cessation of exposure to n-hexane. Results of the nerve conduction studies predominantly showed a decrease in motor and sensory conduction velocities. Between 9 and 12 months after cessation of exposure to n-hexane, 83.3% of patients had a complete clinical recovery. The electrophysiological studies also revealed improvement to the majority of motor and sensory nerve conduction velocities. The results of the visual evoked potential (VEP) studies were considered normal at admission, however, the P100 latencies at the 9-month to 12-month retest had improved (p < 0.05). As the abnormalities identified with clinical examination and nerve conduction studies, and the subclinical abnormalities revealed through VEP assessment, could be reversed after exposure to n-hexane had ceased, the clinical prognosis was usually good.

Brucella: a cause of peripheral neuropathy.

Brucellosis is a common infectious disease in Mediterranean countries. We evaluated the peripheral nerve involvement in patients with brucellosis. Thirty-eight patients with brucellosis were examined. Four of them were excluded because of B(12) deficiency and diabetes mellitus. Thirty-four patients were included. The average age was 43.08 +/- 15.3 years. Patients were divided into two groups according to the abnormality in their peripheral nervous system (PNS) examination. All patients underwent nerve conduction and needle electromyography EMG studies. Twenty normal healthy subjects were used as a control group. Axonal sensorimotor neuropathy was determined in 12 patients who also had abnormality in PNS examination. After 6 months of treatment, nerve conduction studies were nearly normal in these patients. The EMG findings of the remaining 22 patients were normal, as well as the clinical examination. However, the motor conduction velocities of median (p < 0.001), peroneal (p < 0.001), and ulnar (p < 0.05) nerves were decreased, F wave latencies were prolonged in the posterior tibial and peroneal nerve, and distal latency was also prolonged in the posterior tibial nerve (p < 0.05) when compared to healthy subjects. Sensory conduction velocities of the median (p < 0.001), ulnar and sural (p < 0.05) nerve were also decreased. Brucellosis may be considered as a cause of clinical or subclinical peripheral neuropathy and should be evaluated especially in endemic areas.

Levetiracetam monotherapy for late poststroke seizures in the elderly.

Stroke is the most common cause of seizures in the elderly. Antiepileptic drugs are used to treat most patients with late poststroke seizures. The aim of this study was to evaluate the efficacy and tolerability of levetiracetam (LEV) in patients aged 60 or older with late-onset poststroke seizures. This prospective study evaluated patients 60 years of age or older, who had at least two late-onset poststroke seizures and were given LEV monotherapy. Demographic data and seizure and stroke characteristics were recorded. Outpatient visits were made after 2, 4, 6, 9, and 12 months and every 3 months thereafter, and the effectiveness and tolerability of LEV were investigated. Thirty-four patients with a mean age of 69.76+/-6.41 were included in this study. Average seizure frequency before treatment was 3.61+/-3.02/month. Mean follow-up time was 17.68+/-3.24 months. At daily doses of 1000-2000 mg, 82.4% of the patients were seizure free, and 7 patients (20.6%) had side effects. LEV was discontinued in one patient because of severe somnolence. Two patients were switched to another antiepileptic drug because of uncontrolled seizures despite an increase in dose up to 3000 mg/day. LEV monotherapy can be effective and well tolerated in elderly patients with late-onset poststroke seizures.

Does the seizure frequency increase in Ramadan?

During Ramadan, the ninth month of the Islamic lunar calendar, adult Muslims are required to refrain from taking any food, beverages, or oral drugs, as well as from sexual intercourse between dawn and sunset. In this study, we aimed at discovering alterations in drug regimens and the seizure frequency of epileptic patients during Ramadan (15 October 2004-13 November 2004). In the 3 months following Ramadan in the year 2004, 114 patients with epilepsy who were fasting during Ramadan were examined at our Epilepsy Department. Of the 114 patients who were included in the study, 38 patients had seizures and one of these patients developed status epilepticus during Ramadan. When the seizure frequency of these patients during Ramadan was compared to that in the last 1 year and last 3 months period just prior to Ramadan, a statistically significant increase was observed (p<0.001). Moreover, there was an important increase in the risk of having seizures in the patients who changed their drug regimens compared with those who did not (p<0.05). In the patients who received monotherapy or polytherapy, no difference in the frequency of seizures during Ramadan was seen (p>0.05). During Ramadan, an increase in the seizure frequency of patients with epilepsy was observed. The most important reason for this situation was the alteration in the pharmacokinetics and pharmacodynamics of drugs, and consequently, in their efficacy. We believe that in the patients who received monotherapy and who did not change their drug regimes, the increase in seizure frequency may have been related to the changes in their daily rhythms, emotional stress, tiredness and their day-long fasting.

Temporal lobe ictal behavioral patterns in hippocampal sclerosis and other structural abnormalities.

Ictal behavioral characteristics may provide clues in determining the nature of the epileptic focus. We defined ictal behavioral characteristics in patients with intractable temporal lobe epilepsy (TLE) who underwent anterior temporal lobectomy (ATL) and lived seizure-free for 2 years of follow-up. Video/EEG data on 282 seizures observed in 48 patients who suffered from TLE and underwent ATL were analyzed. All patients were seizure-free after surgery. We divided the patients into two groups on the basis of the pathological examination. Two hundred and two seizures in 35 patients with hippocampal sclerosis (Group 1) and eighty seizures in 13 patients with other pathological findings, such as tumors, cavernoma, and hamartoma (Group 2), were analyzed. Ictal behavior characteristics were evaluated for each of the seizures recorded in the two groups. Behavioral arrest, bilateral hand automatisms, oral and leg automatisms, and ictal aggression were significantly more frequent in Group 2 (P<0.05), whereas contralateral dystonia of the upper extremity (P<0.05), ipsilateral hand automatisms (P<0.05), ipsilateral hand automatisms in the presence of contralateral dystonia of the upper extremity (P<0.001), contralateral forced head deviation (P<0.05), and secondary generalization (P<0.05) were more significant in Group 1. There was no significant difference in vocalization and ipsilateral nonforced head deviation between the two groups (P>0.05). The number of seizures observed during ictal speech, crying, and postictal nose wiping was not large enough, so differences could not be analyzed. It was concluded that although ictal behavioral characteristics differed between the two groups, certain behavioral patterns may be helpful in differentiating between hippocampal sclerosis and other pathology.

Hush sign: a new clinical sign in temporal lobe epilepsy.

Neurologists have been analyzing the clinical behaviors that occur during seizures for many years. Several ictal behaviors have been defined in temporal lobe epilepsy (TLE). Ictal behaviors are especially important in the evaluation of epilepsy surgery candidates. We propose a new lateralizing sign in TLE originating from the nondominant hemisphere-the "hush" sign. Our patients were 30- and 21-year old women (Cases 1 and 2, respectively). Their epileptogenic foci were localized to the right mesial temporal region after noninvasive presurgical investigations. Case 1 had no cranial MRI abnormality, whereas cranial MRI revealed right hippocampal atrophy in Case 2. These women repeatedly moved their right index fingers to their mouth while puckering their lips during complex partial seizures. We have named this ictal behavior the "hush" sign. Anterior temporal lobectomy with amygdalohippocampectomy was performed in both patients, and pathological examinations revealed hippocampal sclerosis. The "hush" sign no longer occurred after seizures were controlled. They were seizure free as of 30 and 31 months of follow-up, respectively. We believe that the "hush" sign may be supportive of a diagnosis of TLE originating from the nondominant hemisphere. This sign may occur as a result of ictal activation of a specific brain region in this hemisphere.