What is MND

 

Motor neuron disease is a degenerative disorder of the motor neurons which control voluntary muscle activity such as speaking, swallowing, breathing and walking. Disruptions arise in the signal from the motor neurons in the brain, brainstem and spinal cord resulting in gradual weakening, wasting, and twitching ( known as fasciculations) of the muscles.

 

MND is more common in men than women and usually appears after the age of 40 years. The cause is is not known but environmental, toxic, viral and genetic factors are implicated. There may be a higher incidence in sportsmen related to repeated muscle trauma however this is not a proven association. 10 % of cases of MND are inherited and in these patients a defective gene is inherited from one or both parents leading to onset of symptoms even in childhood.

 

MND consists of various subtypes of which Amyotrphic Lateral sclerosis (ALS) is the most common.Symptoms include weakness, muscle cramps and twitching muscles are usually noticed first in the hands and arms or legs and patients may complain of difficulty swallowing.

 

Thereafter speech becomes nasal and slurred and breathing becomes difficult. Clinical signs include spasticity, brisk reflexes and muscle atrophy, eventually patients are unable to use their arms and legs and require assistance with feeding and breathing.

 

There are no specific tests to diagnose MND and early in the disease diagnosis can be difficult. It is important to exclude all other potentially treatable conditions and a thorough neurological examination, EMG ( elctromyography) and NCS ( nerve conduction studies) are performed to aid in the diagnosis of nerve and muscle dysfunction and spinal cord disease.

 

Laboratory screening of bloods and cerbrospinal fluid (CSF) are performed to rule out muscle, nerve and other neurological disorders that can have symptoms similar to MND. MRI brain and spinal imaging is also important in excluding other potentially treatable causes and in confirming MND.

 

There is no treatment that can cure MND. Riluzole which is registered to treat MND may prolong the disease by several months. Treatment otherwise is largely symptomatic in the form of medications that help with symptoms, physical therapy and assistive devices. Prognosis of ALS is generally 2-5 years.