Table 1.
Nerve conduction study parameters and CSF findings of the patient
| Nerve | Muscle | Latency (ms) | Amplitude (mV) | Conduction velocity (m/s) | F-wave latency (ms) | Interpretation |
|---|---|---|---|---|---|---|
| Right median (motor) | APB | Borderline normal (3.92) | Distal: 3.3, proximal: 3.0 | Slowed (44.8) | Prolonged (30.2) | Features of AMAN with mild secondary demyelination (F-wave delay, mild slowing) |
| Left median (motor) | APB | Borderline normal (3.96) | Distal: 1.5, proximal: 1.4 | Slowed (43.8) | Prolonged (32.8) | Axonal pattern |
| Right ulnar (motor) | ADM | Mildly prolonged (3.31) | Distal: 4.3, proximal: 3.9 | Slowed (44.0) | Prolonged (32.2) | Axonal motor neuropathy with mild secondary slowing |
| Left ulnar (motor) | ADM | Prolonged (3.85) | Distal: 3.1, proximal: 1.1 | Slowed (46.0) | Prolonged (NR) | Moderate axonal involvement; slowed velocity suggests secondary demyelination |
| Right peroneal (motor) | EDB | NR | NR | NR | NR | Severe axonal involvement, absent responses |
| Right tibial (motor) | AH | Normal (3.85) | Distal: 3.5, proximal: 2.0 | Slowed (33.6) | Prolonged (57.8) | Severe axonal loss with secondary conduction slowing |
| Right median (sensory) | Index | Prolonged (3.39) | Reduced (4.1 µV) | Slowed (38) | — | Sensory nerves relatively preserved; mild slowing could reflect subclinical involvement |
| Right ulnar (sensory) | Dig V | Prolonged (2.45) | Reduced (3.4 µV) | Slowed (38) | — | Mild sensory slowing; consistent with secondary changes |
| Right sural (sensory) | Calf-ankle | Prolonged (2.92) | Low-normal (4.0 µV) | Borderline (43) | — | Preserved sensory conduction supports AMAN subtype with limited secondary involvement |
| Cerebrospinal fluid (CSF) findings | ||||||
| Parameter | Findings | |||||
| Protein | 52 mg/dL | |||||
| White blood cell (WBC) count | 3 cells/μL | |||||
| Glucose | 68 mg/dL | |||||
| Opening pressure | 9 cm H2O | |||||
| Red blood cells (RBC) | Absent | |||||
| Electro diagnostic parameter | Hadden et al[4] | Rajbally et al[4] | Our Case | Interpretation | ||
| AIDP criteria met | DL >110% ULN, CB, TD, F-wave >120% ULN | Similar with stricter CB (P:D <0.7) | DL normal, no CB/TD, isolated prolonged F-wave | Does not meet AIDP criteria | ||
| CMAP amplitude | D-amp <80% LLN → AMAN | Same | Absent in peroneal, reduced in tibial | Consistent with AMAN | ||
| SNAPs | May be reduced in AIDP | Should be preserved in AMAN | All normal | Supports AMAN | ||
| Motor conduction velocity | <90% LLN in AIDP | <70% LLN in AIDP | Tibial ~32–33.6 m/s (borderline) | Suggests possible secondary slowing | ||
| Final diagnosis according to the criteria | AMAN | AMAN | Fulfills AMAN with mild delayed slowing | Primary AMAN with secondary demyelination | ||