Numbness of hands and feet, an early sign of peripheral neuropathy
Numbness is a sensory dysfunction encompassing the loss of pain, temperature, touch, or vibratory sensation. The severity may vary among individuals. The symptoms are commonly encountered in people of working age to the elderly. Improper posture, nutritional deficiency, medical conditions, and genetic factors are risk factors which can contribute to sensory abnormality. Early detection and treatment can prevent symptom progression and improve the quality of life.
Symptoms above and beyond numbness
Sensory dysfunction from peripheral neuropathy can manifest in various ways:
- Paresthesia: Patients experience numbness with loss of touch or hot/cold sensation. Some may have gait and balance problems as well. Others, on the contrary, may have excessive physical sensitivity including sensation of electric shock, extreme pain sensitivity when lightly touched or stimulated. The locations where this occurs vary; they may be in one or both hands, arms, legs, and feet. Initially, the symptoms may come and go and later become constant. In some cases, symptoms may start in one location and spread to involve other areas later.
- Weakness: Muscle weakness accompanies numbness in the same location. Some may have associated muscle pain.
- Autonomic dysfunction: Common symptoms are excessive sweating, giddiness with postural change or digestive tract problems such as abdominal bloating or constipation.
When to see a doctor
Seek medical attention if you feel less or more than normal level of sensation, have muscle weakness or gait and balance difficulty.
Causes of peripheral neuropathy based on presenting symptoms
1. Numbness on single arm or leg
Numbness on single arm or leg is a sign of diseases involving peripheral nerve, its branches, nerve roots or ganglion. Common causes are carpal tunnel syndrome, peroneal entrapment from sitting cross-legged, nerve root compression by a herniated disc, and inflammation or infection of nerve branches and ganglion. Moreover, if symptoms begin simultaneously at multiple locations on single arm or leg, it may be due to ischemia-induced inflammation from autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid, or from viral hepatitis
2. Numbness of distal arms and legs bilaterally
Numbness of distal arms and legs bilaterally. In patients with progressive severe symptoms, numbness of anterior chest and mid back could develop. If symptoms fully develop within 4 weeks, the cause is usually Guillain-Barré syndrome. If symptoms gradually develop over an interval of more than 8 weeks, then the causes could be autoimmune diseases, diabetes, hypothyroidism, paraproteinemia, vitamin deficiencies, or chemotherapeutic agents.
How is peripheral neuropathy diagnosed?
The diagnostic process begins with a review of the patient's medical history and performing a neurological examination. Sensory system testing involves provoking sensations of fine touch, pain, hot/cold temperature, and vibration together with laboratory procedure known as electrodiagnostic testing including electromyography (EMG) and nerve conduction studies (NCS) which can help with the diagnosis, ascertain the pathology, locate the abnormal nerves, and is useful for the clinical follow-up of neuropathy. The tests can be done in 30-60 minutes as an outpatient. The result of both nerve conduction study and electromyography will be analyzed in conjunction with clinical symptoms to arrive at an accurate diagnosis and devise a suitable treatment plan.
