Tahir Obeid

Juvenile Myoclonic Epilepsy: A 5-Year Prospective Study

Summary: We made a long term prospective study of 66 patients with juvenile myoclonic epilepsy (JME). Prevalence was 10.2% among 672 patients with epilepsies. Sex distribution was equal. Sixty‐three were not diagnosed on referral; JME was not initially recognized in the epilepsy clinic in 22. Clinical typical absence seizures were reported in 33.3%, myoclonic jerks in 97% and generalized tonic‐clonic seizures (GTC) in 78.8% of the patients. Mean age (±SD) at onset was 10.5 ± 3.4 years (range 5–16 years) for absence seizures, 15 ± 3.5 years (range 8–26 years) for myoclonic jerks, and 16 ± 3.5 years (9–28) for GTC. Absence predated myoclonic jerks by 3.9 ± 2.3 years (range‐1–9 years) and GTC by 4.4 ± 2.7 years (range 1–8 years) in 14 (21.2%) patients who manifested all three types of seizure. Absence were never antedated by myoclonic jerks or GTC. Myoclonic jerks occurred on awakening in 87.5% of the patients. GTC occurred mainly on awakening, but other patients had nocturnal or diurnal GTC with no circadian distribution. Neurologic examination was normal for all patients except for tremor of the hands similar to essential tremor, noted in 35% of patients. Computed tomography (CT) brain scans were normal: 93% of patients had precipitating factors: sleep deprivation (89.5%), fatigue (73.7%), photosensitivity (36.8%; television and video games 8.8%), menstruation (24.1% of women), mental concentration (22.8%), and stress (12.3%). Incidence of JME among siblings (13 of 41 examined families) implies an autosomal recessive mode of inheritance for this Arab population. EEGs were frequently normal in treated patients. At least one abnormal EEG was recorded in 56 (84.9%) patients. Abnormalities consisted mainly of generalized discharges of spike/double spike and/or polyspike and slow wave. Frequent multiple spikes and discharge fragmentations varied from 0.5to 20‐s duration (mean 6.8 s). Twenty (30.3%) had focal abnormalities, and 18 (27.3%) had photoconvulsive discharges. Eighty‐eight percent of patients remained seizure‐free for 3 years of follow‐up. Effective treatment was achieved with valproate (VPA); control of myoclonic jerks was improved with clonazepam (CZP). CZP monotherapy did not consistently prevent GTC. Adding small doses of CZP with simultaneous reduction of VPA was the most effective and better tolerated form of medication, particularly in patients demonstrating an adverse reaction or requiring a large VPA dosage. VPA dosage was successfully reduced in 15 patients who were seizure‐free for >2 years and had infrequent seizures before treatment, but 9 of 11 patients relapsed after VPA discontinuation.

Juvenile Myoclonic Epilepsy: Factors of Error Involved in the Diagnosis and Treatment

Summary: Juvenile myoclonic epilepsy (JME), a common form of idiopathic generalized epilepsy, has a distinct clinical and electroencephalographic profile. Often JME is not recognized, with serious consequences on the sufferers. We examined factors contributing to the missed diagnosis even in an epilepsy clinic. Of 70 JME patients, 66 (91.4%) were not diagnosed on referral and 22 (33%) were not initially recognized in the epilepsy clinic. The correct diagnosis was established after a mean of 8.3 ± 5.5 years from disease onset and an interval of 17.7 ± 10.4 months from first evaluation in the epilepsy clinic. Myoclonic jerks, the hallmark of the disease, were not usually reported by patients. Similarly, relevant questioning may not be included in the history. Absence seizures antedating jerks by many years, myoclonic jerks reported as unilateral, generalized tonic‐clonic seizures occurring during sleep and focal EEG abnormalities are other factors contributing to not recognizing JME. Our study reempha‐sizes the need to have not only a correct seizure diagnosis but also a correct epilepsy‐disease diagnosis.

Juvenile myoclonic epilepsy: a study in Saudi Arabia.

Summary: We studied 50 patients in Saudi Arabia with juvenile myoclonic epilepsy (JME). There was a high positive family history of epilepsy (48.7%) and a high prevalence (10.7%) of other forms of epilepsy. JME was unrecognized at the time of referral for all patients. Age at onset varied from 6 to 28 years with an average of 15.5 years. Treatment was effective with valproate or with clonazepam; 42 patients were seizure‐free for a minimum of 6 months of follow‐up. EEG abnormalities were recorded in 37 patients; photoconvulsive responses were elicited in 15 patients but only 1 was clinically photosensitive.

Clonazepam in juvenile myoclonic epilepsy

Summary: We studied the efficacy of clonazepam (CZP) in control of juvenile myoclonic epilepsy (JME) in 17 patients. CZP was very effective in controlling myoclonic jerks in all patients but did not suppress generalized tonic‐clonic seizures (GTCS). A disadvantage occurs because the patient is deprived of the warning jerks which presage the onset of GTCS. The circadian rhythm of the GTCS was also changed in two patients.

Photosensitive Epilepsies and Photoconvulsive Responses in Arabs

SUMMARY: The occurrence of photosensitivity (PS) was examined in 327 Arabs ≥15 years of age with epilepsy by intermittent photic stimulation (IPS). A control group of 192 nonepileptic Arabs ≥15 years of age were also examined by IPS. Of the epileptic patients, 24 (7.3%) were photosensitive, an incidence comparable to that in whites in contradistinction to the reported rarity among African blacks. This finding indicates that environmental factors, particularly excessive sunshine, does not appear to influence the occurrence of PS among epileptic patients. The occurrence of PS among epileptic patients may depend more strongly on the presence of an epileptic syndrome known to have association with PS.

Bickerstaff brainstem encephalitis: A grave non-demyelinating disease with benign prognosis

We describe 6 patients with ophthalmoplegia, ataxia and normal or exaggerated deep tendon reflexes. All had been preceded by a febrile illness and had a full recovery without sequelae. The brainstem auditory evoked potentials showed a localised lesion in the upper brainstem while the pattern shift visual evoked potentials were normal and did not show any additional silent lesions. CSF IgG oligoclonal bands were not detected in any of the patients. MRI in 2 patients showed a confluent high intensity lesion in the upper mesencephalon and thalamus involving white and gray matter. Follow-up ranged from 6 to 24 months and showed no relapse.

Clinical and genetic aspects of juvenile absence epilepsy.

Fifteen patients aged 11–25 years (mean 15.37, SD 3.89) suffering from juvenile absence epilepsy are presented. Only 3 (20%) had absences (AS) as the only seizure type, 12 (80%) had associated generalized tonic-clinic seizures (GTCS) and in the remaining 3 with absences and GTCS there was also sporadic myoclonus. We found a higher frequency of AS in our patients by clinical history and video-EEG than has been previously reported. In our patients the mean age of onset in years was 11.4, SD 1.24 for AS, 13.12, SD 2.31 for GTCS and 12.5, SD 2.18 for myoclonus. The correct diagnosis was not made on referrals for any of the patients. It took an average of 3–5.5 years from the onset of the AS (range: 6–120 months) and 2 years from the occurrence of GTCS (average: 1–72 months) to make the correct diagnosis and institute proper treatment, which was valproic acid (VPA). The GTCS were controlled in all patients whereas AS continued in 6 (40%), but to a significantly lesser degree. The frequency and the duration of the GTCS before the start of VPA treatment seemed to have an adverse effect on AS control. We documented no circadian rhythm in either AS or the GTCS, except in 2 patients who had AS and GTCS mainly when they awoke in the morning. The sample size was too small to perform a proper genetic study, though a positive history of epilepsies of mixed types was obtained in 35.7% of the parents and the siblings of the probands.

Cavernous Angioma Presenting as Pregnancy‐Related Seizures

Summary: Purpose: To determine the reason that one‐quarter to one‐third of epileptic women experienced an increased number of seizures during pregnancy. The cause of this increase is not always clearly understood and the principle emphasis of the literature is on the pregnancy‐associated changes of anticonvulsant pharmacokinetics.

Unusual presentation of tuberculous meningitis.

We present 4 cases of tuberculous meningitis with atypical clinical features and CSF findings. Two patients had initially normal CSF examination, one developed internuclear ophthalmoplegia, while the other had deterioration of consciousness. The third patient presented with paranoid psychosis, and the fourth had a picture mimicking acute bacterial meningitis and he developed right hemianopia due to a tuberculoma detected by MRI. All recovered completely with anti-tuberculous treatment.

A unique effect of clonazepam on frontal lobe seizure control.

In a 16-year-old female, clonazepam (CZP) changed randomly occurring intractable tonic seizures of frontal lobe origin to a few sleep seizures when used as an adjunctive therapy. The significance of this change in the seizure pattern is discussed with an explanation of possible pathophysiologic mechanism.