gms | German Medical Science

Normal pressure hydrocephalus (NPH) is a disease of the elderly patient generally without a family history. A familial association has only once been described in a man and his sister (Portenoy K, 1984). We report on identical twins, who became symptomatic at the same time in different towns.

Patient 1 was seen by a neurologist at the age of 72 after a 1 year's history of progressive hypokinetic gait disorder and memory deficits. Urinary function was not impaired. Parkisonism was suspected but the patient did not respond to Levodopa. MRI demonstrated a communicating hydrocephalus. One year later the identical twin, a 73 year old male, presented with a 2 years´ history of progressive gait disturbance, memory deficits, and urinary incontinence. MRI again showed an enlargement of all ventricles. Mental capability was assessed by the mini-mental state examination.

Both patients received one or multiple spinal tap tests resulting in a temporary improvement of the gait ataxia. Diagnosis of NPH was further confirmed by a pathologic lumbar infusion test in case 2. Ventricular peritoneal shunts were implanted using a medium pressure valve (case 1) and a programmable valve with an opening pressure of 120 mm H₂O (case 2). In the uneventful postoperative course, gait ataxia (both cases) and urinary function (case 2) improved. Mini mental state performance remained unchanged (case 2). On 3/12 months follow-up urinary incontinence and gait ataxia had almost completely resolved while memory deficits persisted.

NPH in identical twins indicates a genetic determination that may be due to congenital arrested or to late-onset hydrocephalus. Only in pediatric syndromes have X-linked recessive, autosomal recessive and dominant inheritance been reported.