Table 3

Clinical features in SCA6 compared with SCA1, SCA2, and SCA3

	SCA 1 (n = 10)	SCA 2 (n = 21)	SCA 3 (n = 59)	SCA6 (n = 21)
Age of onset (mean (SD))	37 (7)^***	32 (12)^***	36 (9)^***	52 (12)
(range, y)	(30 - 42)	(12 - 49)	(15 - 56)	(30 - 71)
Duration of disease (mean (SD), range)	7 (4), 2-17	12 (8), 3-30	10 (6), 1-31	11 (10), 1-40
Cerebellar dysfunction	100	100	100	100
Ataxia of gait and stance	100	100	100	100
Limb ataxia	100	100	98	100
Dysarthria	100	100	93	100
Ocular motor disorders	100	83	100	100
Saccadic smooth pursuit	50^**	31^***	94	94
Gaze evoked nystagmus	20^***	38^**	98	94
Reduced saccadic velocity	50	77^***	10	7
Impaired optokinetic nystagmus	78	86	61	70
Impaired vestibulo-ocular reflex	70	71	69	83
Ophthalmoplegia	30	37	57	36
Double vision	10^3-150	0^***	79	58
Extrapyramidal signs	20	48^3-150	19	12
Tremor	0	26	3	6
Akinesia	0	10	8	6
Rigidity	0	5	5	6
Choreiform hyperkinesia	20	0	3	0
Dystonia	0	0	5	0
Myoclonus	0	33^3-150	4	0
Pyramidal affection	70	29	70	47
Spasticity	70	10	63	35
Hyperreflexia	20	5^3-150	49	35
Babinski’s sign	30	24	44^**	0
Peripheral neuropathy	100^**	86^3-150	80^**	41
Hyoreflexia	40	81^***	55^3-150	18
Vibration sense (6/8)	80^3-150	75^3-150	55	35
Impaired kinaesthesia	25	14	16	18
Loss of thermal sense	25	39	90^***	24
Paresis (dorsal foot flexion)	10	29	34^3-150	0
Amyotrophy (foreleg)	30^3-150	25	43^3-150	0
Cramps	57	80	63	36
Intellectual impairment	20	25	5	0
Faciolingual fasciculation	30	11	36^3-150	0
Swallowing problems	44	74	74	50
Incontinence	0	33	30	6