Skip to main content

Table 1 Neurophysiological characteristics of a typical patient with asymmetrical SNAPs (Patient 1) and of a patient with completely absent SNAPs (Patient 2) from these series

From: Cerebellar ataxia with sensory ganglionopathy; does autoimmunity have a role to play?

Subject NCS
Parameter
Median
CMAP
Ulnar (ADM)
CMAP
Tibial
CMAP
Median
SNAP
Ulnar
SNAP
Radial
SNAP
Sural
SNAP
Superficial Peroneal
SNAP
  Side (R) (R) (R) (R) (L) (R) (L) (R) (L) (R) (L) (R) (L)
Patient 1
(Asymmetric SNAPs)
46Y, Female
Amplitude 14.1 mV 10.7 mV 9.2 mV 17.4 μV 6.1 μV 3.1 μV 5.7 μV 18.4 μV 12.4 μV 21.5 μV 12.8 μV 7.7 μV 3.4. μV
Conduction velocity 60 m/s
(Elbow-Wrist)
60 m/s
(Below elbow – Wrist)
70 m/s
(Above elbow – below elbow)
NC 56 m/s
(Digit III –Wrist)
60 m/s
(Digit III –Wrist)
58 m/s
(Digit V –Wrist)
57 m/s
(Digit V–Wrist)
58 m/s
(Forearm- Snuff Box
55 m/s
Forearm- Snuff Box
48 m/s
Calf – lateral malleolus
48 m/s
Calf – lateral malleolus
48 m/s
Leg – Dorsum of the foot
47 m/s
Leg – Dorsum of the foot
Patient 2
(Absent SNAPS)
67Y, Male
Amplitude 8.3 mV 6.3 mV 3.0 mV NR NR NR NR NR NR NR NR NR NR
Conduction velocity 54 m/s
(Elbow-Wrist)
48 m/s
(Below elbow – Wrist)
59 m/s
(Above elbow – below elbow)
NC NA NA NA NA NA NA NA NA NA NA
  1. NCS nerve conduction studies, CMAP compound muscle action potential, SNAP sensory nerve action potential, ADM abductor digiti minimi, R right, L left, NC not checked, NR not recordable, NA not applicable