DESCRIPTION OF CONDITIONS
Wrist Drop | Foot Drop
Also known as radial nerve palsy, is a condition where a person cannot extend their wrist and it hangs flaccidly. To demonstrate wrist drop, hold your arm out in front of you with your forearm parallel to the floor. With the back of your hand facing the ceiling (i.e. pronated), let your hand hang limply so that your fingers point downward. A person with wrist drop would be unable to move from this position to one in which the fingers are pointing up towards the ceiling.
Wrist extension is achieved by muscles in the forearm contracting, pulling on tendons that attach distal to (beyond) the wrist. If the tendons, the muscles, or the nerves supplying these muscles, are not working as they should be, wrist drop may occur.
The following may result in wrist drop: Persistent injury to the nerve is also a common cause through either repetitive motion or by applying pressure externally along the route of the radial nerve as in the prolonged use of crutches or extended leaning on the elbows. For this reason, radial nerve palsy is also sometimes referred to as crutch paralysis, Saturday Night Palsy (individual falls asleep with the back of their arm compressed by the back of a chair), or Honeymoon Palsy (one individual sleeps on the arm of another individual).
The diagnosis for wrist drop frequently includes nerve conduction velocity studies to isolate and confirm the radial nerve as the source of the problem. Other screening tests include the inability to extend the thumb into a "Hitchhiker's sign". Plain films can help identify bone spurs and fractures that may have injured the nerve. Sometimes MRI imaging is required to differentiate subtle causes.
Initial management includes splinting of the wrist for support along with Chiropractic, Osteopathic medicine, Physiotherapy and Occupational Therapy. In some cases, surgical removal of bone spurs or other anatomical defects that may be impinging on the nerve might be warranted.
Foot drop is a gait abnormality in which the dropping of the forefoot happens due to weakness, irritation or damage to the common fibular nerve including the sciatic nerve, or paralysis of the muscles in the anterior portion of the lower leg. It is usually a symptom of a greater problem, not a disease in itself. It is characterized by inability or impaired ability to raise the toes or raise the foot from the ankle (dorsiflexion). Foot drop may be temporary or permanent, depending on the extent of muscle weakness or paralysis and it can occur in one or both feet.
Foot drop is characterized by steppage gait (high stepping). While walking, people suffering the condition drag their toes along the ground or bend their knees to lift their foot higher than usual to avoid the dragging. This serves to raise the foot high enough to prevent the toe from dragging and prevents the slapping. To accommodate the toe drop, the patient may use a characteristic tiptoe walk on the opposite leg, raising the thigh excessively, as if walking upstairs, while letting the toe drop. Other gaits such as a wide outward leg swing (to avoid lifting the thigh excessively) may also indicate foot drop.
Foot drop can be caused by nerve damage alone or by muscle or spinal cord trauma, abnormal anatomy, toxins or disease. Diseases that can cause foot drop include direct hit to posterolateral neck of fibula, stroke, amyotrophic lateral sclerosis (ALS or Lou Gehrig's Disease), muscular dystrophy, Charcot Marie Tooth disease, multiple sclerosis, cerebral palsy, hereditary spastic paraplegia, Guillain–Barré syndrome and Friedreich's ataxia. It may also occur as a result of hip replacement surgery or knee ligament reconstruction surgery.
Initial diagnosis often is made during routine physical examination. Such diagnosis can be confirmed by a medical professional such as a neurologist. A person with foot drop will have difficulty walking on his or her heels because he will be unable to lift the front of the foot (balls and toes) off the ground. Therefore, a simple test of asking the patient to dorsiflex may determine diagnosis of the problem. There are other tests that may help determine the underlying etiology for this diagnosis. Such tests may include MRI, MRN, or EMG to assess the surrounding areas of damaged nerves and the damaged nerves themselves, respectively.
The underlying disorder must be treated. For example, if a spinal disc herniation in the low back is impinging on the nerve that goes to the leg and causing symptoms of foot drop, then the herniated disc should be treated. If the foot drop is the result of a peripheral nerve injury, a window for recovery of 18 months to 2 years is often advised. If it is apparent that no recovery of nerve function takes place, surgical intervention to repair or graft the nerve can be considered, although results from this type of intervention are mixed. Non-surgical treatments for spinal stenosis include a suitable exercise program developed by a physical therapist, activity modification (avoiding activities that cause advanced symptoms of spinal stenosis), injections, and anti-inflammatory medications like ibuprofen or aspirin. If necessary, a decompression surgery that is minimally destructive of normal structures may be used to treat spinal stenosis.
Ankles can be stabilized by lightweight orthoses, available in moulded plastics as well as softer materials that use elastic properties to prevent foot drop. Additionally, shoes can be fitted with traditional spring-loaded braces to prevent foot drop while walking. Regular exercise is usually prescribed.
If you or someone you know suffers or suspects they may have wrist drop or foot drop and are looking for a specialist neurologist, please feel free to contact Synapse Neurology for a consultation on 03) 8582 6945.