(Last Updated On: April 25, 2017)

Polyneuropathies are diseases of the peripheral nerves when peripheral nerves are affected in groups and in varying patterns. These diseases result in various clinical expressions of diseased nerves. Polyneuropathies are classified according to their clinical picture and underlying pathology. Here is an account of types and causes of polyneuropathies.

1. Sensory Motor Polyneuropathy:

Sensory symptoms of a neuropathy can be very painful — Pins and Needles Sensations as Neuropathy Symptoms

This type of nerve diseases affect both sensory and motor nerves resulting in loss of both sensations and muscle power. These can be caused by following:

I. Alcohol

II. Diabetes Mellitus

III. Hypothyroidism

IV. Guillain-Barre Syndrome (GBS)

V. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

VI. Hereditary Motor & Sensory Neuropathy (HMSN)

VII. Vasculitis

VIII. Paraneoplastic Neuropathy

IX. Paraproteinemic Neuropathy

2. Sensory Polyneuropathy:

Distribution of signs and symptoms in sensory neuropathy. — Peripheral Sensory Neuropathy

Only sensory nerves are affected by sensory polyneuropathy, resulting in loss of sensations only while muscle power remains preserved. Here is a list of causes of sensory polyneuropathy:

I. Diabetes Mellitus

II. Hypothyroidism

III. Drugs, such as isoniazid and vincristine

IV. Vitamin B12 deficiency

V. Paraneoplastic

VI. Amyloidosis

VII. HIV

VIII. Leprosy

3. Motor Polyneuropathy:

Foot deformity in motor neuropathy — Pes Cavus in Motor Polyneuropathy

Only motor nerves are affected in this variety resulting in weakness or paralysis of muscles while sensations remain intact. Here is a list of causes of this type of polyneuropathy.

I. Guillain-Barre Syndrome (GBS)

II. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

III. Multifocal Motor Neuropathy (MMN)

IV. Porphyria

V. Lead

VI. Diphtheria

4. Focal and/or Multifocal Neuropathies:

Biological cascade leading to multifocal motor neuropathy — Mechanisms involved in the development of multifocal motor neuropathy.

This kind of neuropathies have no set pattern and can occur in any part of the body any time or can occur in various parts of the body simultaneously. Causes of this kind of neuropathies include:

I. Connective Tissue Diseases

II. Vasculitis

III. Granulomatous Disorders such as Wegener’s Granulomatosis or Sarcoidosis

IV. Malignant Infiltration

V. Nerve Compression such as Peroneal Nerve Compression

VI. Hereditary Neuropathy with Liability to Pressure Palsy (HNLPP)

VII. HIV

VIII. Leprosy

IX. Diabetes Mellitus

X. Fabry’s Disease