Table 2.
Investigations
| Investigation | n/available data (%) |
|---|---|
| Abnormal sensory nerve conduction study | 95/95 (100) |
| Sensory action potential upper limbs | |
| Reduced | 40/92 (45) |
| Absent | 52/92 (57) |
| Sensory action potential lower limbs | |
| Reduced | 15/90 (17) |
| Absent | 75/90 (83) |
| Reduced amplitude of compound motor action potential in upper limbs | 2/94 (2) |
| Reduced amplitude of compound motor action potential in lower limbs | 10/93 (11) |
| Spinal cord atrophy on cervical MRI | 19/42 (45) |
| Posterior column changes on cervical MRI | 4/34 (12) |
| Cerebellar atrophy on brain MRIa | 57/91 (63) |
| Cerebral atrophy on brain MRIa | 17/91(19) |
| White matter changes on brain MRI | 31/91 (34) |
| Bilateral vestibular impairment | 48/53 (91) |
| Autonomic dysfunction | |
| Parasympathetic dysfunctionb | 9/36 (25) |
| Sympathetic dysfunctionc | 11/32 (34.4) |
| Combined parasympathetic and sympathetic dysfunction | 10/42 (23.8) |
a
One patient only had brain CT scan.
b
Heart rate during Valsalva manoeuvre, deep breath and standing.
c
Blood pressure during change in posture and handgrip; sympathetic sudomotor response.