Fatal Familial Insomnia (FFI) is a rare, inherited prion disease characterized by a progressive insomnia, cognitive impairment, endocrine disturbances ­ including abnormal circadian rhythms of GH, prolactin and melatonin ­ as well as autonomic and motor dysfunctions.¹

The common presenting symptom of insomnia² is refractory to traditional hypnotics such as barbiturates and benzodiazepines, even when high dosages (diazepam 50 mg i.v.) are used.³ A recent case report suggests that the investigational drug Gamma Hydroxy Butyrate (GHB), may be a safe and useful intenention in patients with FFI.⁴ We report a case of a 35 year old, Chinese male with established FFI whose sleep complaint and overall condition temporarily worsened with GHB treatment.

CASE HISTORY:
The patient presented with a 3 month history of difficulty initiating and maintaining sleep as60ciated with jerking movements of the lower limbs which later progressed to include arm and whole body movements. Occasional apneic episodes, sleep talking and "dream enactment" were witnessed. The family history revealed the patient's father developed an illness at the age of 51 characterized by insomnia, limb jerking and mental deterioration with death occurring 8 months after illness onset. A paternal aunt and uncle of the patient, aged 48 and ~38 respectively had similar illnesses The autopsy report (1978) of the aunt was available and showed degeneration in the thalamus, axonal torpedoes and Purkinje cell loss in the cerebellar cortex and some patchy neuronal loss and gliosis in the olive. A definitive post­mortem diagnosis was not made although a form of familial Jakob­Creutzfeldt disease was suspected.

Following the onset of the insomnia, the patient developed specific neurological signs including myoclonic jerking during sleep. Subsequently he acquired diplopia, dysarthria, hypophonia and dysphagia. A polysomnogram was performed (09/04/1995) and showed marked insomnia, periodic limb movements, hypopneas and whole­body myoclonic jerking.