Nocturnal Paroxysmal Dystonia (NPD), two cases report

Abstract

Nocturnal Paroxysmal Dystonia (NPD) is a rare condition characterized by recurrent attacks during NREM sleep of variable duration (seconds to minutes), with a complex clinical expression: repetitive stereotyped dystonic, ballistic or choreoathetoid movements involving single or all extremities and neck. It is associated with other conditions such as paroxysmal arousals, episodic nocturnal wanderings, dyskinetic or semipurposeful movements and vocalizations, often no ictal epileptic in surface EEG activity, and normal brain neuroimaging. Nowadays, it is clear that most of patients who fit the diagnosis of NPD have a form of sleep-activated focal epilepsy (nocturnal frontal lobe epilepsy). Our aim is to present two patients diagnosed with NPD. It is a descriptive study, enrolling two patients with NPD diagnosis. We report two cases. The first one, a 13 years old boy without relevant personal and family medical history, who debuted at 5 years old with dystonic and dyskinetic attacks during sleep that occurred many times per night. The second case is a 39 years old man, without relevant personal and family medical history. Since aged 31 years, he complained attacks of motor agitation with stereotypical movements every night and often several times per night. Both patients remained without neurological abnormalities in physical examination and brain neuroimaging. The EEGs during wakefulness and sleep were normal. Initially they were diagnosed as NREM parasomnia and followed many years without evidence of developing any neurocognitive disorder or neurological impairment, despite no treatment. The attacks of Nocturnal Paroxysmal Dystonia are a form of nocturnal frontal lobe epilepsy. The application of deep brain electrodes has led to the recognition that ”hypermotor seizures” may also be found in seizures originated from the temporal lobe and the insula. Functional brain imaging in frontal lobe seizures confirms that the peculiar motor patterns involve mesial and especially cingulate, motor areas. It is necessary to keep into consideration this rare and not well-known entity in the differential diagnosis of atypical parasomnias. Although the latest advances in Neurosciences, the polysomnography and the clinical history continue being pillars in the diagnosis of nocturnal frontal lobe epilepsy so the neurophysiological studies must always be considered when the diagnostic of a parasomnia is not well established. Dres. Quintana, Sáez y Paradinas.