Table 1. Clinical features of Viliuisk encephalomyelitis in affected members of 6 families*.

Feature	Family 1			Family 2		Family 3		Family 4			Family 5		Family 6
	1-1	1-2	1-3	2-1	2-2	3-1	3-2	4-1	4-2	4-3	5-1	5-2	6-1	6-2	6-3
Sex	F	F	F	F	F	F	M	M	F	F	F	F	M	F	F
Age at onset, y	16	38	26	16	44	31	21	51	47	36	20	34	46	37	53
Febrile stage of illness
Duration, wk	7	11	2	2	10	ND	2	ND	ND	4	ND	1	ND	6	26
Maximum temperature, oC	40.5	39	38	37.9	39.8		39.0			39.0		ND		38.5	38.8
Reduced level of consciousness	++	+++		+	+++		+			++				+	+++
Generalized seizures	++			+						+
Neck rigidity and Kernig sign	+	++		+	++		+			+					+
Nausea, vomiting	+	++	+		++									++	+
Upper motor neuron pattern of muscle weakness	+				+					+				+
Relapse of febrile illness	+	+								+					+
Outcome	a	d	a	a	d	a	a	a	a	a	a	a	a	a	d
Advanced disease
Cognitive decline	++		+	++		m.i.	++	++	++	++	++	++	+	++
Apathy	+			+			++		+	+		+		+
Dysarthria	+++		++	++		++	+	++	+	++			+	+
Dysphagia							+	+		+		+
Brisk deep tendon reflexes	++		++	++		++	++	++	+	++	+	++	+	++
Spastic tetraparaparesis	+++		+	++		+	++	+	++	+++	–	+	+	–
Increased muscle tone	+		+	+		+	++	+	+	++	–	+		+
Babinski sign	+		+	+			+	+	+	+		+
Spastic gait	+++		++	++		+	+++	+	+	+	+	+	+	+
Falls	+			++			+			+			+
Sphincter dysfunction	+			++			++					+
Extrapyramidal rigidity	+		+	++		+	++	++	+	+			+	+
Obesity	+		+	+										+
Cachexia		+			+					++					+
Overall duration of illness	18 mo	11 wk	A	48 mo	10 wk	17 y	24 mo	9 y	6 y	11 mo	11 y	23 mo	13 y	27 mo	26 wk

*ND, not documented; m.i., memory impairment; +, mild; ++, moderate; +++, strong; –, not expressed; d, died within acute phase; a, advanced disease developed; A, alive.