Synonyms:
Mononeuropathy multiplex a.k.a. mononeuritis multiplex
Diagnosis:
This is a clinical plus electrophysiological diagnosis
Clinical features:
a syndrome with involvement of at least two separate nerves. Usually sensorimotor.
Findings on investigations:
+NCS:
- Axonal, asymmetrical i.e. >50% difference between sides, distribution of multiple separate nerves
- Decreased SNAP
- Decreased CMAP
- Motor conduction velocities: mild decrease (remaining >75% of lower limit of normal),
- Distal latencies: normal or <25% increase
- F-waves: normal or <25% increase
+EMG:
- Denervation, axonal, multifocal
Investigations to consider:
- ESR, CRP, ANA screen, ENA panel (anti- dsDNA, anti-Sm, anti-RNP, SSA, SSB, anti-Jo-1, antitopoisomerase ‘formerly anti Scl-70’, antinucleolar, anticentromere), ANCA (c-ANCA, p-ANCA), Complement C3, C4 and CH50
- Anti-GM1: multifocal motor neuropathy
- ACE levels and Ca++: raised in sarcoidosis
- Lyme serology, HIV serology
Nerve biopsy:
- Vasculitis, leprosy
Causes of Mononeuropathy multiplex a.k.a. mononeuritis multiplex:
Vasculitis: (axonal), common
- Rheumatoid arthritis (axonal)
- SLE, systemic sclerosis
- Polyarteritis nodosa
- Wegener’s granulomatosis
- Cryoglobulinemia (rare)
Infections:
- HIV(axonal)
- Lyme disease
- Mycobacterium leprae (Leprosy)
Demyelination:
- Mutifocal form of CIDP (demyelinating)
- Multifocal motor neuropathy MMN (demyelinating)
Others:
- Diabetes mellitus, common
- Sarcoidosis, rarely
- Amyloidosis
- Hypereosinophilia syndrome
- Sickle cell disease
- Subacute asymmetric idiopathic polyneuropathy
- Migrant sensory neuritis a.k.a. Wartenberg’s disease (pure sensory, axonal)
Causes of mononeuritis multiplex with lymphocytic meningitis:
- Lyme Neuroborreliosis
- Neurosarcoidosis
- Zoster sine herpete
- Uveo-meningeal syndromes