Familial Creutzfeldt-Jakob disease in Finland: epidemiological, clinical, pathological and molecular genetic studies.

In 1974-1984 30 patients died with a diagnosis of Creutzfeldt-Jakob disease (CJD) in Finland (annual mortality rate of CJD 0.9 per million population for the years 1979-1984). Six of these patients (20%) were familial, all belonging to the same kindred. The pedigree now includes 15 affected members in four generations, and the occurrence of disease is consistent with an autosomal dominant mode of inheritance. The clinical features of CJD in this family are in most respects typical of the familial disease described elsewhere. However, the mean age at onset is 47, periodic EEG activity has not been observed, and the mean duration of illness of 27.5 months is longer than usual for either familial or sporadic CJD. Neuropathological examination of brain biopsy and autopsy specimens revealed spongiform change without amyloid plaques, and brain tissue from one patient transmitted disease to a capuchin monkey. In an analysis of the histocompatibility antigens of the family, CJD was not linked with a single haplotype, but at least 12 out of 13 CJD patients shared the HLA antigen A28. Molecular genetic studies disclosed a new G-to-A mutation in codon 178 of the PRNP gene (resulting in a substitution of asparagine for aspartic acid) in the DNA of eight family members with CJD but not in any of ten currently healthy first degree relatives of the patients, or 86 controls. The codon 178 mutation thus seems to co-segregate with CJD in this family. Linkage analysis gave a LOD score value of 3.6.

Microangiopathy with encephalopathy, hearing loss and retinal arteriolar occlusions: two new cases.

Two young women developed encephalopathy, hearing loss and retinal arteriolar occlusions. Their behaviour became immature and cognitive functions were severely impaired. One of the patients underwent brain biopsy, which showed several microinfarcts in both white and grey matter and microangiopathic changes, with thickened arteriolar segments staining intensely for laminin and fibronectin. These findings support the concept of a new type of microangiopathy involving the brain, inner ear and retina.

Suspected dementia: evaluation of 323 consecutive referrals.

A neurological outpatient department studied 323 consecutive referrals for suspected dementia: 135 (41.8%) were not demented. Of the patients 12.1% had diffuse cognitive disorder; 10.2% circumscribed memory disorder; 0.9% other circumscribed cognitive disorder, 14.2% psychiatric disorder, and 4.3% were judged to be normal. Of the nondemented, 44.1% had a potentially treatable cause for their cognitive symptoms; in 27.4% it was depression. The total of demented patients was 188 (58.2%): 38.8% had primary degenerative dementia; 37.2% vascular dementia including combined degenerative and vascular dementia; and 23.4% had a specific cause. Patients with specific cause were significantly younger than those with other causes of dementia. A potentially treatable cause was found in 10.7% of all demented patients, the most common being metabolic disorders, meningioma, hydrocephalus, subdural haematoma, and depressive pseudodementia.

Status epilepticus and alcohol abuse: an analysis of 82 status epilepticus admissions.

In 1979-80, 82 cases of grand mal status epilepticus (71 patients, 39 male and 32 female) were admitted to the Casualty Department of Meilahti University Hospital in Helsinki, Finland. The cause of the underlying epilepsy was symptomatic in 43 cases (52.4%) and idiopathic in 19 cases (23.2%). In 6 cases (7.3%), there was a history of alcohol withdrawal seizures, and in 14 cases (17.1%) there was no earlier history of convulsions. Status epilepticus was associated with an acute or progressive cerebral disorder in 14 episodes. These comprised 6 bouts of status with brain tumour, 4 with acute stroke and 4 with brain injury. Alcohol abuse preceded the status in 29 episodes (35.4%), 23 of which occurred in men (53.5% of the male cases). Excessive use of alcohol was the only obvious precipitating factor for status in 16 cases, and in 6 cases the status presented as a prolonged alcohol withdrawal seizure. A change or irregularity of anticonvulsive drug therapy could be documented in 14 cases and an acute infection outside the central nervous system in 7 cases. Intravenous diazepam, used as the only therapy for status epilepticus, was effective in 58 of 78 episodes. In 7 cases of prolonged status, a thiopental sodium anaesthesia proved effective. The total mortality was 4.2%, including 2 deaths from concomitant extracerebral disorders and one late death from brain metastasis.

Familial Creutzfeldt-Jakob disease.

A Finnish family is described with 9 cases of presenile dementia in 3 generations. The mean age at onset was 52 years (range 46--62 years). Progressive dementia, upper motor neuron signs, muscular rigidity, and twitching, irregular tremors were consistent features in the 6 clinically investigated patients and were associated with spongiform change in the cerebral cortex of one autopsy and two brain biopsy cases. The EEG showed progressive slowing without the occurrence of repetitive high-voltage complexes at any stage of the disease. The average duration of the disease (21 months, range 11--36 months) was longer than in the sporadic form of CJD. The occurrence of CJD within this family follows a pattern consistent with an autosomal dominant mode of inheritance, suggesting the possibility of vertical transmission of the presumptive causative agent for example by genomic integration or transplacental passage. However, the occurrence of the disease only through the paternal line of relationships and the presence of a discordant twin pair argue strongly against transplacental passage or transmission via mother's milk. Simple contact infection also seems unlikely, as conjugal cases were not found among the 7 married patients. The interval between the death of the last affected member in generation IV and the time of onset of the disease in the first affected member of generation V was 10 years. Thus setting a minimum incubation period if case-to-case transmission were occurring. To evaluate the role of a genetically determined susceptibility to infection studies on the HLA antigens and other genetic markers are in progress.