Neurodegenerative Disease

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton and Kim Jackson  

Introduction

NDDs may affect mobility

Neurodegenerative diseases (NDD) are diverse conditions characterized by selective dysfunction and ongoing loss of neurons, glial cells and the neural networks in the brain and spinal cord. Accordingly they causes diverse problems examples being with movement (called ataxias), mental functioning (called dementias) and a person's ability to move, speak and breathe. NDD are incurable and debilitating conditions, and are becoming increasingly prevalent in part due to global population ageing NDD impact many families - these disorders are not easy for the individual nor their loved ones.

They are diverse in their pathophysiology. Examples of NDD are:

• Alzheimer’s disease (AD) and other dementias
• Parkinson’s disease (PD) and Parkinsonism
• Prion disease
• Synucleinopathies
• Motor neurone diseases (MND)
• Huntington’s disease (HD)
• Spinocerebellar ataxia (SCA)
• Spinal muscular atrophy (SMA).

Epidemiology

Based on WHO data, 50 million people worldwide had neurological disorders (NDs) in 2019, projected to reach 152 million by 2050. This represents a massive and growing patient population requiring neurological physiotherapy intervention.

• The Global Burden of Disease Study 2021 shows neurological conditions are now the leading cause of global disease burden, creating unprecedented demand for physiotherapy services:
• 3.4 billion people (43.1% of global population) affected by neurological conditions in 2021
• 443 million disability-adjusted life years (DALYs) caused, indicating substantial functional impairment requiring rehabilitation
• 18.2% increase in total DALYs since 1990, reflecting growing physiotherapy caseloads
• Low and middle-income countries bear over 90% of the neurological disease burden while having 70 times fewer neurological professionals per 100,000 people than high-income countries - highlighting critical gaps in physiotherapy service provision.

The top neurological conditions requiring physiotherapy intervention include stroke, migraine, dementia, diabetic neuropathy, epilepsy, and autism spectrum disorder. Stroke and diabetic neuropathy are particularly relevant to physiotherapists, as these conditions commonly present with movement disorders, balance impairments, and functional limitations that respond to physiotherapy interventions including gait re-education, strengthening, balance training, and spasticity management.

This data emphasizes the critical role neurological physiotherapists play in addressing movement and functional impairments across this expanding patient population, particularly in developing comprehensive rehabilitation programs for stroke survivors and managing peripheral neuropathy complications..

Etiology

Wheelchair provision

The majority of NDDs are due to a combination of genetic and environmental factors. This makes it difficult to predict who will develop disease. The greatest known risk factor for many NDDs is age.

• Some NDDs are caused by inherited genetic changes. These disorders run in families: the faulty gene is transmitted from parents to their children.eg. Huntington’s disease, and rare cases of motor neurone disease and Alzheimer’s disease.
• Environmental factors also contribute to NDDs. eg. There is evidence linking Parkinson’s disease with long-term exposure to pesticides, toxins and chemicals.

Pathology

Amyloid plaque in AD

What We Know About Disease Mechanisms:

• Multiple causes: faulty genes, brain inflammation, cell damage, abnormal proteins
• Key genes: APOE (Alzheimer's), LRRK2 (Parkinson's)
• Brain immune cells malfunction, causing inflammation
• Progressive nerve cell death in specific brain areas
• Protein clumps form before symptoms appear
• Main protein disorders: amyloidoses, tauopathies, synucleinopathies

NDDs can be classified according to:

1. Primary clinical features, include: Alzheimer’s disease (AD); Dementia; Parkinson’s disease (PD) Parkinsonism, Motor Neurone Disease; Huntington’s disease (HD)
2. Anatomic distribution of neurodegeneration, include: Frontotemporal dementia; Extrapyramidal disorders; Spinocerebellar ataxia; Spinal muscular atrophy (SMA)
3. Principal molecular abnormality, include: Prion disease; Synucleinopathies. Amyloidoses,.

Earlier classifications focused on the clinical presentation, whereas as more and more NDDs are understood at a biochemical level, classifications have shifted towards the underlying pathological processes.

Diagnosis

Ageing is a risk factor for NDD

NDDs are often presented as a distinct entity, however there is often overlap. None of the neurodegenerative disorders have perfect diagnostic accuracy. While pathological analysis is considered to be the gold standard in a wide spectrum of diseases, it cannot be applied to neurological processes. Studying disease heterogeneity at autopsy is key to understanding discrepancies between clinical and pathological diagnoses. This is a critical concept because there are many efforts to develop biomarkers to diagnose these diseases and to monitor disease progression in clinical trials

Treatment

There are currently no drugs to prevent or cure NDDs. Treatment aims to control symptoms and includes:

• Medications
• Physiotherapy eg for gait training
• Speech pathology eg for swallowing and speech training
• Occupational therapy eg for home modifications
• Psychiatry eg for depression.

Treatment Approaches Being Developed

• Neuromodulation (electrical/magnetic brain stimulation)
• Immune system modification, brain plasticity enhancement
• Targeting the brain's natural repair processes

Where Research is Heading:

• Anti-inflammatory drugs targeting brain immune cells
• Treatments to improve cellular cleanup and energy production
• Better diagnostic markers for early detection
• Combined therapies attacking multiple disease pathways
• Nanotechnology to deliver drugs across blood-brain barrier
• Smarter clinical trials using genetic profiling.

Physiotherapy

NDDs are a group of progressive neurological diseases that cause worsening motor, cognitive and autonomic dysfunction over time. Physiotherapy play a role in the management of these conditions and helping to improve quality of life for these individuals. Most patients are referred to physiotherapists treatment. See individual links for physiotherapy management.