Parkinson

• Parkinson's Disease


  A slow, chronic, progressive disease of the nervous system
• Parkinson's disease


  • First described by James Parkinson in 1817
  • Pathology defined in early 1900s
  • Treatment revolutionized in 1960s with Levodopa

  
• Parkinsonism


  Parkinson's disease and parkinsonian syndrome - a group of disorders characterized by four cardinal signs: bradykinesia or hypokinesia, rigidity in skeletal muscle, resting tremor, and postural instability

  
• Parkinson's disease (PD)


  • A progressive neurological disorder that results from loss of dopaminergic neurones in the substantia nigra
  • Cause unknown, but believed to be associated with genetic and environmental factors
  • Characterized by motor and non-motor symptoms

  
• Quality of life (QoL) severely affected by both motor and non-motor symptoms of Parkinson's disease

  
• Input from a multidisciplinary team improves outcomes for patients and carers with Parkinson's disease
• Prevalence of Parkinson's disease

  • Varies from 10 to 400 to 100,000
  • Incidence increases with age
  • Affects 1.4% of the population over the age of 55
  • Gender differences - males slightly higher than females up to age 74, then females slightly higher

  
• Types of Parkinsonism


  • Idiopathic (Parkinson's disease)
  • Drug induced (e.g. phenothiazines)
  • MPTP toxicity
  • Post-encephalitic
  • Wilson's disease

  
• Parkinsonism plus


  • Progressive supranuclear palsy (Steele Richardson syndrome)
  • Multiple system atrophies (Olivopontocerebellar atrophy, Striatonigral degeneration, Progressive autonomic failure (Shy-Drager syndrome))

  
• Parkinson features can occur in Alzheimer's disease, head trauma (e.g. boxers), and multiple cerebral infarcts

  
• Pathophysiology of Parkinson's disease

  • Due to degeneration of neurons in the striatonigral pathways, there is a deficiency in the level of dopamine
  • Dopamine is the neurotransmitter in the striatonigral pathway that inhibits the excitation of the cholinergic pathway which has acetylcholine as the neurotransmitter
  • Decrease in dopamine level removes the inhibitory influence on the cholinergic pathway causing excessive excitation of the extrapyramidal system (reticulo and rubro), which cause increased tone in the agonist and antagonist

  
• Etiologies of Parkinsonism


  • Idiopathic (unknown reason, e.g. Parkinson's disease)
  • Vascular (multi-infarction in the brain)
  • Infection (viruses, e.g. influenza virus)
  • Toxicity (toxic chemicals, e.g. manganese, carbon monoxide, cyanide)
  • Drugs (phenothiazines, butyrophenones, tetrabenazine)
  • Multiple system degeneration (Alzheimer's disease, Shy-Drager syndrome, supranuclear ophthalmoplegia, Wilson's disease)
  • Metabolic (abnormal calcium metabolism)
  • Traumatic (multiple brain damages, e.g. boxers)

  
• Clinical features of Parkinson's disease

  • Posture (Simian posture)
  • Balance (tendency to topple forward, short and shuffling gait, difficulty in turning around or initiating walking)
  • Learnt and voluntary movements (akinesia, reduced range and speed of movements)
  • Automatic movements (mask-like face, impaired automatic swallowing and coughing)
  • Rigidity (increased muscle tone, two types: lead pipe and cog wheel)
  • Tremor (usually asymmetrical or unilateral, 4-6 cycles per second)

  
• Non-motor symptoms of Parkinson's disease

  • Neuropsychiatric (dementia, depression, anxiety, visual hallucinations)
  • Autonomic (constipation, urinary incontinence, hyperhidrosis, sialorrhea, postural hypotension)
  • Sleep disorders (rapid eye movement sleep behaviour disorder, restless leg syndrome, vivid dreams, narcolepsy)
  • Sensory symptoms (pain, paraesthesia)

  
• Medical management of Parkinson's disease

  • Aims to supplement dopamine by administering dopamine precursor levodopa and reduce acetylcholine with anticholinergic drugs
  • First line treatment includes levodopa coupled with carbidopa, non-ergot derived dopamine agonists and monoamine oxidase B (MAO-B) inhibitors
• Surgical management of Parkinson's disease

  Stereotactic thalamotomy - making a stereotactic lesion in the globus pallidus or ventrolateral nucleus of the thalamus to relieve disabling tremor

  
• General health management for Parkinson's disease

  • Maintain a sensible, well-balanced diet including plenty of fluids and fibre
  • Eat at regular intervals throughout the day
  • Engage in physical exercises to maintain muscle tone, joint mobility, cardiovascular and respiratory function, and good posture
  • Participate in mental stimulating activities like crosswords and quizzes
  • Time medication to suit daily routine
  • Intersperse activity with rest to avoid over-tiring
  • Avoid upper respiratory tract infections
• Psychological considerations in Parkinson's disease

  • Depression, anxiety, embarrassment, confusion, loss of motivation, changes in attitudes, fear
  • Encourage active participation in treatment planning
  • Identify interests and sources of motivation to establish balance
  • Use relaxation techniques to reduce anxiety
  • Discuss depression openly with patient and family
  • Engage in activities and develop interests outside home for companionship and stimulation
  • Address absent-mindedness and thought blocks, which do not indicate mental deterioration, by using notes and prompts
  • Overcome fear by encouraging and supporting to find information about the disease
  • Deal with embarrassment on an individual basis using problem-solving and self-help approaches
• Levodopa is converted into dopamine in the brain and can be used as an effective treatment for PD.
• Levodopa is converted into dopamine in the brain and can be used as an effective treatment for Parkinson's disease.
• The pathophysiology of PD involves the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) leading to decreased striatal dopamine levels.
• The pathophysiology of Parkinson's disease involves the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to decreased levels of dopamine in the striatum.
• Parkinson's disease is characterized by tremors, rigidity, bradykinesia, postural instability, and dyskinesias
• Parkinson's disease is characterized by tremors, rigidity, bradykinesia (slow movement), postural instability, and dystonia.
• Drug therapy for PD includes levodopa/carbidopa, dopamine agonists, monoamine oxidase B inhibitors, anticholinergics, amantadine, and selegiline.
• Tremor - involuntary rhythmical movement that occurs at rest or during voluntary movements
• Carbodopa reduces peripheral conversion of levodopa to dopamine, allowing more levodopa to reach the central nervous system.
• Bradykinesia - slowness of movement due to reduced amplitude of motor unit discharge
• Deep brain stimulation (DBS) is a surgical procedure that involves implanting electrodes deep within specific regions of the brain to alleviate symptoms of PD.
• Dopamine agonists are drugs that mimic the effects of dopamine on the nervous system and can be used to treat symptoms of Parkinson's disease.