Syndromes Mimic Nerve Entrapment of Peripheral Neuropathy
AANS 2015 MEETING HIGHLIGHT
The challenge posed by differential diagnosis of peripheral neuropathy was the topic of a presentation given by Holly S. Gilmer, MD, Associate Professor of Neurosurgery at the William Beaumont Oakland University School of Medicine, Royal Oak, Michigan. “I was asked to present this topic to colleagues who specialize in neurosurgical procedures for pain and nerve problems because we frequently encounter patients who are very complex,” said Dr. Gilmer. She spoke at the American Association of Neurological Surgeons 83rd Annual Scientific Meeting in Washington, DC.
Causes of peripheral neuropathy include:
- Alcohol abuse
- Inherited or familial Charcot-Marie-Tooth syndrome
- Autoimmune diseases such as Sjögren’s syndrome, systemic lupus erythematosus, rheumatoid arthritis, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, and necrotizing vasculitis
Neural anatomy of peripheral neuropathy is characterized by:
- Entrapments that follow nerve distribution
- Motor and sensory loss on history and physical examination
- Electromyography and nerve conduction studies
- Imaging that excludes structural problems rather than neuropathy
- Response to nerve injection(s). Relief of pain with injection of local anesthetic and/or steroids around a nerve confirms that nerve as the source of pain
- Cause related to other problems
In cervical or lumbar radiculopathy, the following may play a role:
- History of neck or back pain
- Tinel’s sign
- Magnetic resonance imaging or myelography that shows disc herniation or tumor
- Electromyography and nerve conduction studies
- Conservative treatment such as physical therapy
- Lateral femoral cutaneous nerve entrapment
- Peroneal neuropathy
- Piriformis involvement
- Sciatic nerve entrapment
- Tarsal tunnel and/or sural entrapment
Pain in the head and neck can be caused by:
- Greater, lesser, or a combination of greater and lesser occipital neuralgia
- Cluster headaches
Peripheral neuropathy related to Sjögren’s syndrome may involve:
- Burning pain, numbness or weakness from distal to proximal, large- or small-fiber neuropathy, and areflexia
- Mononeuritis multiplex
- Trigeminal or glossopharyngeal neuralgia and optic neuritis
- Electromyography and nerve conduction studies, as well as skin biopsy
Systemic Lupus Erythematosus
Florica et al, in 2011, characterized the peripheral neuropathy of systemic lupus erythematosus as:
- Most commonly, polyneuropathy, mononeuritis multiplex, or mononeuropathy (vasculitis and subsequent ischemia or nerve infarction)
- Asymmetric vs stocking-glove
- Edema leading to compression/entrapment
The typical signs of systemic lupus erythematosus are butterfly rash, fatigue, alopecia, pericarditis/pleuritis, kidney failure, and myalgia. Symptoms of systemic lupus erythematosus may vary widely with each individual but include pleural effusions, heart problems, lupus nephritis, arthritis, and Raynaud’s phenomenon.
Peripheral neuropathy associated with rheumatoid arthritis was described by Lisak in 2014. Peripheral neuropathy occurs in 10% of patients with rheumatoid arthritis. Large- and small-fiber neuropathy are observed, as well as distal sensory neuropathy, distal sensory/motor polyneuropathy, and mononeuropathy multiplex. Entrapments of the carpal and tarsal tunnels are observed, as well as ulnar neuropathy.
Type 2 Diabetes
Peripheral neuropathy occurs in up to 50% of patients with type 2 diabetes. It involves acute sensory neuropathy with severe lower extremity pain and chronic sensorimotor neuropathy that is asymptomatic in up to 50% of cases, insidious, and which carries autonomic dysfunction and late complications of ulceration and amputation.
- Diabetic mononeuropathy is painful, acute in onset, and occurs in a self-limiting course of approximately 6 weeks.
- The entrapment neuropathies of type 2 were described by Vinik et al in 2004. Entrapment is gradual in onset, progressive, and persists without intervention. The most common entrapments are carpal tunnel syndrome, ulnar neuropathy, peroneal nerve entrapment, meralgia paresthetica of the lateral femoral cutaneous nerve, and tarsal tunnel syndrome.
Peripheral neuropathy is the most common deleterious effect of alcoholism, occurring in 25%–66% of chronic alcoholics. This peripheral neuropathy is characterized by distal lower extremity paresthesias, dysesthesias, and/or weakness. Paresthesias occur most commonly in the feet and toes in a symmetric pattern and progress proximally. Gait ataxia, with difficulty walking or frequent falls, is observed.
Twenty million Americans suffer from peripheral neuropathy, and the disorder is expected to grow, with 86 million Americans (more than one in three adults) estimated to be prediabetic. Nine of ten of these individuals do not know they have the condition. Differential diagnosis is crucial, as in the coming years, neurosurgeons may expect to treat peripheral neuropathy in increasing numbers of patients. “It is very important to exclude medical causes of pain prior to subjecting a patient to surgery, or to a treatment for a different medical condition which will not be effective,” said Dr. Gilmer.
May 27, 2015