Central Hypoventilation Syndrome during Awake and Sleep

Central hypoventilation syndrome (CHS) can be caused by any lesions to the medullary respiratory centers, cerebral cortex, corticospinal pathways, and their connections. We report 5 patients with central hypoventilation syndrome and analyzed 26 patients who experienced central hypoventilation syndrome during sleep and waking states. We compared initial clinical symptoms and signs, maximal neurologic deficits, brain MRI and pathologic findings, and associated autonomic dysfunctions. The patients with respiratory failure during waking states showed quadriplegia, a rapidly progressing respiratory failure. The patients who had automatic respiratory failure showed mild hemiparesis, bulbar dysfunction, dysautonomia, and subacute to chronic recurrent respiratory failures. These results support the concept of two separate respiratory systems: a voluntary system and an automatic system. The respiratory management of these patients with central hypoventilation syndrome should be considered critical to their survival.

Blockade of the Subthalamo-nigral Pathway Prevents the Motor Component of Pilocarpine Induced Generalized Convulsive Seizure in Rats

BACKGROUND: The substantia nigra pars reticulata is a critical site for the control of epileptic seizures. The potentiation of the inhibitory gamma-amino butyric acid (GABA) ergic input from the striatum to the substantia nigra pars reticulata suppresses primary or secondary generalized seizures in rats. Recent data suggests that the projection from the subthala-mus to the substantia nigra pars reticulata plays a critical role in the control of some forms of epileptic seizures. METHODS: We examined the possible involvement of the excitatory glutamatergic input from the subthalamic nucleus (STN) to the substantia nigra in pilocarpine-induced seizures by the direct injection of GABA receptor agonist (muscimol) and n-methyl- D-aspartate (NMDA) receptor antagonist (MK-801) into the substantia nigra pars reticularis (SNr) and the subthalamic nucleus respectively. Sprague-Dawley rats were classified into four groups depending on the pretreatment; the injection of saline (STN sham) or muscimol (STN) into the subthalamic nucleus, and the injection of saline (SNr sham) or MK-801 (SNr) into the substantia nigra. Seizure was induced by the intraperitoneal injection of pilocarpine (400 mg/kg). RESULTS: Mean seizure stages in the STN group (1.5 +/-0.5) and SNr group (1.3 +/-0.5) were significantly lower than STN sham group (4.8 +/-0.4) and SNr sham group (4.8 +/-0.4) (P <0.05). Electroencephlograms showed typical status epilepticus patterns in the sham operation group but only discrete ictal discharges with slowing and intermittent ictal spikes were shown in both STN and SNr group. Viable cell numbers in the CA1 and CA3 in STN and SNr groups were significantly higher than those of the sham group (P <0.05). CONCLUSIONS: These results provide evidence for the role of subthalamo-nigral projections in the modulation of pilocarpine-induced seizures.

Two Cases of Sporadic Encephalitis Lethargica

We present two patients with clinical features suggestive of a hyperkinetic form of encephalitis lethargica described by von Economo. While undergoing treatment for viral meningoencephalitis, they both developed comatose mentality, oromandibular dyskinesia, chorea, myoclonic jerk, oculogyric crisis, opistotonus, respiratory failure, and autonomic dysfunction. One patient died of autonomic failure while the other improved several months later. In both patients, cerebrospinal fluid exmamination revealed only pleocytosis. A brain MRI and EEG showed no specific findings. In order to control severe hyperkinetism and autonomic failure, medical treatments including L-dopa, clonazepam, and steroid pulse therapy were administereed in both cases while electroconvulsive therapy was tried in one of the cases. However, they all failed. These cases and previous reports informed us of the presence of sporadic form of encephalis.