Congenital Hypomyelinative Neuropathy
Congenital hypomyelinative neuropathy has a presentation in many ways similar to Werdnig-Hoffmann disease. A sensory deficit is present but is usually clinically undetectable in neonates. The first clue to the diagnosis of hypomyelinative neuropathy is a very slow motor nerve conduction or the presence of elevated cerebrospinal fluid protein in the presence of a normal white blood cell count.
The diagnosis is established by sural nerve biopsy. The biopsy shows little or no myelin sheath around the axons and no evidence of demyelination or onion bulb formation in sural nerve biopsy. This entity may occur sporadically or follow an autosomal recessive or dominant pattern of inheritance. In most instances, this disease is not progressive.

Acute Polyneuropathy
Acute polyneuropathy or Guillain-Barre syndrome may occur in the neonatal period and should be considered if a previously healthy neonate develops hypotonia with decreased dynamic tone after an apparent viral illness. Cerebrospinal fluid proteins are increased and motor nerve conduction is very slow after 2 weeks. These patients usually recover. This entity is very rare. Immunoglobulin is the treatment of choice for acute polyneuropathy. The effectiveness of immunoglobulin in the neonatal period is unknown.

Chronic Inflammatory Demyelinating Polyneuropathy
Chronic inflammatory demyelinating polyneuropathy presents very much like acute polyneuropathy in a newborn. It is the history of chronicity or recurrence as the patient gets older that raises the possibility of this diagnosis. Nerve conduction is decreased. Nerve biopsy shows decreased myelin, evidence of segmental demyelination and remyelination, and subperineural and endoneural edema with inflammatory cells. The diagnosis is established by sural nerve biopsy. Treatment with steroids is effective.