O'Neill F. D'Cruz

Improvement of epileptic seizure control with treatment of obstructive sleep apnoea

Sleep deprivation increases the risk of recurrent seizures in epileptic patients. We identified 10 patients with recurrent seizures and sleep disruption related to obstructive sleep apnoea. Two patients were treated with positional therapy and the remaining eight patients were treated with continuous positive airway pressure. Three of the patients became seizure free and a fourth patient had a greater than 95% reduction in seizure frequency following only the initiation of therapy for the sleep apnoea. Three of these four patients responding to therapy, had a state-dependent seizure pattern. Two of the four responders did not exhibit the typical body habitus for obstructive sleep apnoea. Three additional patients improved in seizure frequency with change in anticonvulsant medication and treatment of the obstructive sleep apnoea. The remaining three patients had less than 50% reduction in seizure frequency with treatment of the obstructive sleep apnoea. These results indicate sleep disruption caused by sleep apnoea may increase the seizure frequency in some epileptic patients. Regardless of body habitus, epilepsy patients should be questioned carefully for a history of sleep disturbance and state dependence to their seizures. Treatment of sleep disorders in this population may lower the frequency of recurrent seizures.

Möbius syndrome: evidence for a vascular etiology.

We report five infants with restricted lateral gaze, facial diplegia, feeding difficulty, and/or respiratory disorders without significant pulmonary disease. Viral studies were negative in all patients. Two children had radiologic findings that included brain-stem hypoplasia and symmetric calcification in the dorsal tectum at the junction of the midbrain and pons. Autopsy of one of these two children demonstrated capillary telangiectasia in the mesencephalon and pons. The other three children had normal computed tomographic (CT) scans. However, their autopsies revealed focal brain-stem necrosis with calcifications but without vascular malformation. We suggest that the capillary malformations in one of our patients directly resulted in a vascular-induced necrosis and the manifestation of Möbius sequence. The similarity of symmetric neuropathologic findings in the three other patients and the CT scan in the one surviving patient suggest focal hemodynamic changes restricted to the posterior circulation, indirectly supporting a vascular theory of embryopathogenesis. (J Child Neurol 1993;8:260-265).

Möbius syndrome in infant exposed to cocaine in utero

The pathophysiology of Möbius syndrome has been debated for decades. A vascular etiology is currently favored because it explains the wide clinical spectrum of this syndrome. An infant is reported who was born with Möbius syndrome after a pregnancy complicated by heavy maternal use of cocaine and alcohol. We speculate that cocaine-induced vasoconstriction at a critical time of cerebrovascular development produced a vascular disruption sequence leading to the Möbius syndrome.

Symptomatic cataplexy in pontomedullary lesions

Cataplexy is a cardinal manifestation of the narcolepsy syndrome. Although symptomatic narcolepsy is well described, isolated cataplexy is extremely rare. We reviewed clinical and radiologic data in two patients with isolated symptomatic cataplexy and associated CNS disease. In an HLA-DR2–positive patient with chronic progressive MS, we confirmed cataplexy by observation of reported spells. MRI revealed diffuse white-matter lesions involving the medial medulla, pons, and subcortical white matter; protriptyline provided symptomatic relief. A second patient with a pon-tomedullary pilocytic astrocytoma developed infrequent but recurrent cata-plectic attacks in association with sleep fragmentation due to nocturnal cough and nausea. MRI revealed an enhancing lesion involving the dorsal pons and medulla. Genetic predisposition and sleep fragmentation may precipitate symptomatic cataplexy in patients with structural pontomedullary lesions.

Efficacy of antiepileptic drugs in adults predicts efficacy in children A systematic review

Objective: Due to the challenges inherent in performing clinical trials in children, a systematic review of published clinical trials was performed to determine whether the efficacy of antiepileptic drugs (AEDs) in adults can be used to predict the efficacy of AEDs in the pediatric population. Methods: Medline/PubMed, EMBASE, and Cochrane library searches (1970–January 2010) were conducted for clinical trials of partial-onset seizures (POS) and primary generalized tonic-clonic seizures (PGTCS) in adults and in children <2 and 2–18 years. Independent epidemiologists used standardized search and study evaluation criteria to select eligible trials. Forest plots were used to investigate the relative strength of placebo-subtracted effect measures. Results: Among 30 adjunctive therapy POS trials in adults and children (2–18 years) that met evaluation criteria, effect measures were consistent between adults and children for gabapentin, lamotrigine, levetiracetam, oxcarbazepine, and topiramate. Placebo-subtracted median percent seizure reduction between baseline and treatment periods (ranging from 7.0% to 58.6% in adults and from 10.5% to 31.2% in children) was significant for 40/46 and 6/6 of the treatment groups studied. The ≥50% responder rate (ranging from 2.0% to 43.0% in adults and from 3.0% to 26.0% in children) was significant for 37/43 and 5/8 treatment groups. In children <2 years, an insufficient number of trials were eligible for analysis. Conclusions: This systematic review supports the extrapolation of efficacy results in adults to predict a similar adjunctive treatment response in 2- to 18-year-old children with POS.

Anticonvulsants-induced chorea: a role for pharmacodynamic drug interaction?

Chorea is a rare side effect of anticonvulsants. We describe three patients who developed chorea secondary to anticonvulsant combination use. A mechanism to explain this finding is proposed. After identification of an index case with anticonvulsant-induced chorea, we reviewed the electronic data base records for all patients with seizures followed in the epilepsy clinics at our university-based hospital for cases of dyskinesia associated with anticonvulsants. Two additional patients, one adult and one pediatric patient were identified. Three patients developed chorea while receiving combination anticonvulsants. Two patients had transient chorea that resolved with withdrawal of one of the drugs. All three patients were using phenytoin and lamotrigine in combination when the chorea started, chorea improved with tapering one of the medications. Polytherapy with certain anticonvulsants may predispose patients to drug-induced chorea. A particular increased risk was seen with combinations that have phenytoin and lamotrigine. This could be due to an additive or a synergistic effect on central dopaminergic pathways.

Mobius syndrome: Electrophysiologic studies in seven cases

Mobius syndrome is characterized by congenital facial diplegia, frequent impairment of gaze, variable involvement of other cranial muscles, and various musculoskeletal anomalies. The site of dysfunction remains debatable. We performed detailed electrophysiologic studies in 5 children and 2 adults with Mobius syndrome to better delineate the pathophysiology of this disorder. Sensory and motor conduction studies were normal in the extremities. Facial compound muscle action potential amplitudes were reduced in all patients. The blink reflex R1 responses were unobtainable unilaterally in 2 patients and unobtainable bilaterally in 3 patients. Otherwise, R1 and R2 latencies were variably prolonged. The jaw jerk and masseter silent periods, tested in 2 patients, were normal. Detailed electromyographic studies of facial muscles revealed multifocal, chronic neurogenic changes. The findings indicate a brain stem process predominantly affecting the facial nuclei and their internuclear connections, rather than a supranuclear or muscular site of involvement.

Feasibility and acceptance of salivary monitoring of antiepileptic drugs via the US Postal Service.

Salivary and serum levels of phenobarbital, carbamazepine, and phenytoin are closely correlated. Salivary monitoring of antiepileptic drugs has a number of advantages including the potential for home collection if measured levels are unaffected by transit in the mail. Saliva was collected from 60 adult and 42 pediatric patients in the clinic. A control aliquot was immediately frozen, and a second aliquot was packaged and mailed to the laboratory. Patients were also asked to collect another sample at the same time on the following day and mail it to the laboratory. On receipt, all samples were held frozen and analyzed as a single batch by fluorescence polarization immunoassay. The effects of mailing, the duration in transit, and the season were assessed by multivariable, repeated-measures analysis of variance. One hundred two saliva samples were collected in a mean of 2.6 minutes, and the mailed aliquot was received in a mean of 6.4 days. Two children and 3 adults (4.9% of total) preferred blood collection, but the rest preferred saliva collection or had no preference. There was no significant difference between the control sample and the clinic mailed samples for any of the 3 medications. There were no significant effects of the duration in transit or the season on reliability. Transit of saliva samples in the mail does not adversely affect accuracy of antiepileptic drug measurement. Patients prefer and can successful collect saliva samples at home. Home monitoring of salivary antiepileptic drug levels is a cost-effective technique that deserves additional study.

Obstructive sleep apnea in epilepsy.

Obstructive sleep apnea can affect an individual with epilepsy profoundly. These relatively common disorders can coexist and potentially exacerbate each other. The identification and appropriate treatment of OSA may have far-reaching consequences in improving a patients quality of life and recurrence of seizures. Clinicians must be aware of the relationship of these disorders and keenly question epilepsy patients, regardless of their body habitus, regarding potential symptoms of sleep apnea. Although the underlying pathogenic mechanisms are unclear, we can model the information gained from the observations to further the understanding of the relationship between sleep and epilepsy.

Narcolepsy in a 12-month-old-boy.

Narcolepsy, although frequently beginning in childhood, is usually diagnosed in young adults. The diagnostic symptoms of narcolepsy are usually less typical in the young child, and sleep studies have not been standardized. We present a 12-month-old child with symptoms typical for narcolepsy who shows improvement with non-pharmacologic narcolepsy therapy. (J Child Neurol 2000;15:145-146).