According to the World Health Organisation (WHO), neurological disorders are any diseases affecting the entirety of the nervous system (i.e. the central and peripheral nervous systems). These will be conditions involving the brain, spinal cord, cranial nerves, peripheral nerves, nerve roots, autonomic nervous system, neuromuscular junction and muscles.
Categories of Neurological Disorders
Neurological disorders can be classified based on their affectation of the Central Nervous System (CNS) or the Peripheral Nervous System (PNS). It is worthy to note that disorders of the nervous system can affect both adults and children.
Disorders of the CNS
Neurological conditions affecting the CNS include:
- Alzheimer's Disease: Alzheimer's disease (AD) is a neurodegenerative disease that is characterized by damage to areas of the brain that are responsible for thinking, learning and memory i.e cognition. This is largely due to the accumulation of certain proteins- beta-amyloid plaques and tau tangles within the brain. The role of physiotherapy in providing regular exercise to prevent cognitive decline in patients with AD is largely supported by evidence. It achieves this due to factors such as neurogenesis and anti-inflamatory effects that help lower the pathophysiological hallmarks of the disease.
- Multiple System Atrophy: MSA is a progressive and highly debilitating disease of the CNS that is associated with Levo-dopa unresponsive parkinsonism and cerebellar, autonomic, motor and non-motor symptoms
- Rett Syndrome: RTS is a rare genetic disorder causing neurodevelopmental anomalies that result in severe mental and physical disability. It is common among females
- Traumatic Brain Injury: Occuring in both children and adults, TBI is defined according to Menon et al "as an alteration in brain function or other evidence of brain pathology, caused by an external force"
- Stroke: There are majorly two types of stroke- ischaemic and haemorrhagic. Ischaemic stroke occurs largely due to arterial occlusion in the brain, while haemorrhagic stroke occurs as a result of blood vessel aneurysms that eventually rupture within the brain. Stroke cases are consequent on a number of risk factors that can be termed either modifiable (physical inactivity, obesity,, hypertension, diabetes, smoking, excessive consumption of alcohol) or non-modifiable (age, sex, genetics).
- Parkinson's Disease: Also known as "the shaking palsy", PD is consequent of death and loss of dopaminergic neurons in the substantia nigra of the thalamus and an accumulation of lewy bodies. PD is characterized by tremor at rest that eases off with voluntary movement, rigidity, bradykinesia, hypokinesia and akinesia.
- Migraine: is a chronic neurovascular condition that is characterized by severe headache that is usually one sided. This headache is usually accompanied by photophobia and nausea.
- Cerebral Palsy: According to Rosenbaum et al, "Cerebral palsy (CP) describes a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication, and behaviour, by secondary musculoskeletal problems.
- Spinal Cord Injury: SCI can either be traumatic (e.g. stab injuries, road traffic accidents, etc) or non-traumatic.
- Multiple Sclerosis: MS is an autoimmune, neurological condition affecting more women than men. Charcot's triad of MS include: nystagmus, intention tremor and cerebellar dysarthria.
Disorders of the PNS
Conditions affecting the PNS are as follows:
- Erb's Palsy: See the video below to learn more about Erb's palsy 
- Bell's Palsy: Also known as lower motor neuron facial palsy, Bell's palsy is the sudden weakness of one mirror half of the face. Its risk factors include: infection of the middle ear, exposure to extreme cold upper respiratory tract infection, water retention in pregnancy, viral infection etc. Clinical features include facial deviation to the unaffected side, paralysis of the muscles of facial expression on the side of the nerve injury.
- Diabetic Neuropathy: Also known as distal symmetric polyneuropathy, diabetic neuropathy is a loss of sensory function that begins distally and is charcterized by aching muscular pain, numbness and loss of joint position sense.
- Guillain-Barre Syndrome: GBS is an acute paralytic demyelinating polyneuropathy that is often preceded by respiratory or gastrointestinal tract infection. It is often charaterized by extensive flaccid weakness, symmetrical ascending paralysis, altered sensation, autonomic disorders such as: irregularities in blood pressure, cardiac arrythmias, excessive or no sweating, etc. Medical management is usually by plasmapharesis, immunoglobulin therapy and steriods. Goals of physiotherapy management are set according to the phase of the condition.
- Alcoholic Neuropathy: Characterized by myalgia (muscle pain), dysaesthesia and ataxia, alcoholic neuropathy occurs from chronic and long term alcohol consumption. Those who continuously consume alcohol have been shown to be more affected than occasional drinkers. Risk factors apart from length of alcohol consumption include being male, type of alcohol consumed and genetic predisposition.
- HIV Neuropathy: Presenting as a sensory neuropathy that is often painful, HIV neuropathy is a chronic neurological complication of the HIV infection
- Myasthenia Gravis: Often accompanied by a progressive easy fatiguability with increased activity, ptosis, difficulty swallowing and possible affectation of the respiratory muscles. MG is an autoimmune condition of the neuromuscular junction that affects select muscle groups resulting in unstable weakness of these muscles
- Cauda Equina Syndrome: See the video below for an overview of CES 
Relevance to the Neurophysiotherapist
It is important that the neurophysiotherapist knows and understands the mechanisms underlying the neurological conditions that he encounters in daily practice. This knowledge will aid accurate physiotherapy diagnosis and enhance structuring of appropriate treatment regimen suited for the different patients and their presenting conditions.
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