Grading

Bland

Modified grading by Hirani

Grade 1

Inching, palm/wrist median/ulnar comparison, ring finger double peak

Early:

SCV = 45-50 m/s interpeak potentials in digit IV > 0.5 ms, Distal Motor Latency (DML) < 4.2 ms. Amplitude of sensory and motor potentials ≥ 5

Grade 2

Mild Sensory: Sensory conduction velocity (SCV < 40 m/s DML < 4.5 ms

Mild sensory:

SCV = 40-44.9 m/s with normal sensory amplitude (NSA), DML, amplitude and CV

Grade 3

Moderately Severe: DML > 4.5 ms and < 6.5 ms with Sensory nerve action potentials (SNAP) preserved

Mild sensory motor:

SCV = 40-44.9 m/s with NSA, DML > 4.2 ms with normal motor amplitude (NMA) and normal CV (NCV)

Grade 4

Severe: DML > 4.5 ms and < 6.5 ms with absent SNAP

Moderate sensory:

SCV < 40 m/s with NSA, normal DML, NMA and NCV

Grade 5

Very Severe: DML > 6.5 ms.

Moderate sensory motor:

SCV < 40 m/s with NSA, DML > 4.2 ms and MNA and NCV

Grade 6

Extremely Severe : Motor nerve action potentials (MNAP) < 0.2 mV,

Severe Sensory motor:

Absent or < 3 µV SNAP with SCV < 30 m/s and DML > 4.2 ms with either slow or normal MCV and or NMA

Grade 7

Extremely severe:

SNAP and CMAP absent, but recordable from both median and ulnar 2^nd lumbricals with prolonged median 2^nd lumbrical response compared to ulnar lumbricals

Grade 8

Complete:

SNAP and CMAP absent and absent median 2^nd lumbrical and present ulnar 2^nd lumbrical.