PARKINSON’S DISEASEKhairul Nizam bin Abdul Rahman4262143008NeurologyBPY 1Sir Jibi

INTRODUCTION

• Parkinson’s disease (PD) is a chronic progressive neurodegenerative disorder and is the second most common cause of chronic neurological disability. Although PD is usually classified as a movement disorder, it also causes disorders of cognitive function.

ETIOLOGY

• The term parkinsonism is a generic term used to describe a group of disorders with primary disturbances in a dopamine systems of basal ganglia.

• Parkinson’s disease or idiopathic parkinsonism is the most common form.• Secondary parkinsonism results from a number of different identifiable

causes including viruses, toxins, drugs, and tumors.• Parkinsonism-plus syndromes refers to those condition that mimic PD in

some respects, but the symptoms are caused by other neurodegenerative disorders.

PATHOPHYSIOLOGY

• Parkinson’s disease is defined by (1) degeneration of dopaminergic neurons in the BG in the pars compactus of the substania nigra that produce dopamine and (2) as the disease progresses and neurons degenerate, the presence of cytoplasmic inclusion bodies called, Lewy bodies.

PATHOPHYSIOLOGY

• Loss of dopaminergic pigmented neurons in the substania nigra (SN) pars compacta with dopaminergic deficiency in the putamen and caudate nucleus.

• Dopamine loss in other brain areas including the brainstem, thalamus and cortex also occurs.

• Degeneration of the dopaminergic nigrostriatal pathway to the basal ganglia results in underactivity of the direct motor pathway (normally facillates movement) and overactivity of the indirect motor loop (normally inhibits movement).

• This results in inhibition of the motor cortex manifested with bradykinesia and rigidity.

PATHOPYSHIOLOGY

• Lewy bodies, fibrillary intracellualar eosinophilic inclusions, and high concentrations of alpha-synuclein, ubiquitin, tauprotein, tuberculin, and other proteins are found in the SN, LC and other areas of the brain and are a marker for neuronal degeneration.

• Degeneration of the locus coeruleus LC, which contains noradrenergic neurons, also occurs in PD. Norepinephrine is thought to be neuroprotective and loss of LC neurons may be associated with a worsening of disease progression and the behavioural symptoms of PD.

• Molecular events thought to be associated with the neurodegeneration of PD include mitochondrial dysfunction, oxidative stress, abnormal folding and accumulation of alpha-synuclein, abnormal phosphorylation and dysfunction of the ubiquitin proteasome system.

1)The cortex will increase the inhibitory action of neostriatum.2)Due to increased inhibitory action,the globus pallidus internus inhibitory action is decreased or inhibit by neostriatum.3)When inhibitory action of the globus pallidus decreased,the excitatory action of thalamus is increased.4)The thalamus excites the cortex,thus movement initiated.5)The substantia niagra compacta will receive a cortical input from the motor cortex that a movement will occur.The dopamine neurotransmitter will activate the cortical input.6)Once receive the cortical input,the substantia niagra compacta will stimulate the direct pathway and inhibit the direct pathway.7)In Parkinson disease,there will be decreased in dopamine that will cause inactivation of the cortical input.8)Inactivation in cortical input will make the complication in substantia niagra to stimulate direct pathway and inhibit direct pathway.9)Thus,Parkinson disease associated with the decrease of dopamine cause substantia niagra cannot receive a cortical input from cortex to stimulate movement.

STAGES OF PARKINSON’S DISEASEStages 1• Lesions are found in the medulla oblongata Stages 2• Pathology is expanded to involve lesions of the caudal raphe nuclei, the gigantocellular reticular nucleus,

and coeruleus-subcoeruleus complex.Stages 3• Involvement of the nigrostriatal system is apparent Stages 4 • Lesions are also found in the cortex Stages 5 • Pathology is extended to involve the sensory association areas of the neocortex and prefrontal neocortex.Stages 6 • Pathology is extended to involve the sensory association areas of the neocortex and premotor areas.

CLINICAL FEATURES Major symptoms:• Bradykinesia• Tremor• Rigidity • Postural Instability

Other motor symptoms:• Gait• Loss muscle performance• Loss motor function • Sensory problem• Dysphagia • Speech disorder • Cognitive dysfunction• Autonomic dysfunction• Sleep disorders• Depression and anxiety

BRADYKINESIA

• Bradykinesia is a poverty of voluntary movement with a slower initiation of movement.

• And a progressive reduction in the speed and amplitude of repetitive actions.• Weakness, tremor and rigidity may contribute to bradykinesia.• Bradykinesia is a mandatory sign; no bradykinesia means no PD.

TREMOR

• Tremor involves involuntary shaking or oscillating movement of a part or parts of the body resulting from contractions of opposing muscles.

• In early stages, most patient experience a slight tremor of the hand or foot on one side of the body, or less commonly in the jaw or tounge.

• Tremor is known as resting tremor because it is present at rest, suppressed briefly by voluntary movement and disappears with sleep.

• Tremor in lower limbs is most apparent while the patient is supine.• Tremor of the head and trunk can be seen when muscles are used to maintain an

upright posture against gravity.

RIGIDITY

• Rigidity is experienced as stiffness and muscular pain.• Increase resistance to passive motion.• Patients frequently complain of heaviness and stiffness of their limbs.• It is felt uniformly in both agonist and antagonist muscles.• Spinal stretch reflexes are normal.• Rigidity is fairly constant regardless of the task, amplitude, or speed of

movement.• Prolonged rigidity results in contracture and postural deformity.

POSTURAL INSTABILITY

• Abnormalities of posture and balance.• Abnormal and inflexible postural responses controlling their centre of mass

within their base of support.• Experience increased difficulty during dynamic destabilizing activities such

as self-initiated movements.• And perform poorly under conditions of perturbed balance.• Difficulty in regulating feed-forward, anticipatory adjustments of postural

muscles during voluntary movements.

GAIT

• Involuntary flexion of the trunk limbs and the neck.• Hesitation in starting to walk.• Steps are short and the feet barely clears the ground as patient shuffles

along.• Once walking started patient takes increasingly short and rapid steps as

though trying to catch up to his centre of gravity.• Freezing briefly when encountering doorways or other obstacles.• Diminished or reduced arm swing.• Inability to make appropriate postural adjustments to tilting and falling.• Anticipatory and compensatory righting reflexes are impaired.

MUSCLE PERFORMANCE

• A reduction in strength is evident in patients in PD.• Torque production is decreased at all speeds resulting in activity limitations

and muscle weakness.• Once initiated, contraction is characterized by multiple bursts and

asynchronization, that is pauses and an inability to smoothly increase firing rate as contraction continues.

• These difficulties are compound during production of complex movements.

MOTOR FUNCTION

• In PD, motor planning deficits are evident, involving a loss regulatory control of both automatic and voluntary movement responses.

• Paucity of movements occurs with less accurate movements over all.• This deficit in accuracy becomes more pronounced as the patient attempts to

increase the speed of movement.• Patients experience difficulty performing complex, sequential, or

simultaneous movements.

SENSORY SYMPTOMS

• Patients with PD do not suffer from primary sensory loss.• However, 50% experience paresthesias and pain including sensations of

numbness, tingling cold, aching pain, and burning.• Most patients with PD loss sense of smell (anosmia)

DYSPHAGIA

• Impaired swallowing is present.• Is the result of rigidity, reduced mobility and restricted range of movement. • Demonstrates abnormal tongue control and problems with chewing, bolus

formation, delayed swallow response, and peristalsis.• Dysphagia can lead to choking or aspiration pneumonia and impaired

nutrition with significant weight loss.

SPEECH DISORDER

• Patients with PD experience hypokinetic dysarthria, which is characterized by decreased voice volume, monotone speech, imprecise or distorted articulation and uncontrolled speech rate.

• Patient experience timing difficulty of vocal onsets and offsets.• Voice becoming monotonous, exhibiting reduced volume and lack of rhythm

and variety of emphasis.• Often associated with problem of swallowing leading to drooling.

COGNITIVE DYSFUNCTION

• Impairments in cognitive function can be mild or severe.• PD dementia occurs in approximately 20%-40% of patients.• Dementia associated with PD is characterized by loss of executive functions

(planning, reasoning, abstract thinking, judgment) and changes in visuospatial skills, memory and verbal fluency.

• Bradyphrenia, slowed thinking is seen in patients with PD.

DEPRESSION AND ANXIETY

• Demonstrate a variety of symptoms including feeling of guilt, hoplessness and worthlessness, loss of energy , poor concentration, deficits in short term memory, loss of ambition, and disturbances in appetite and sleep.

• Suicidal thoughts may also be present.• Hypomimia, a reduction in facial expressiveness, can give the appearance of

depression.

SLEEP DISORDERS

• Patients can experience excessive daytime somnolence (sleepiness).• At night, insomnia (disturbed sleep pattern).• This includes problems in falling asleep, staying asleep, and goof quality of

sleep.• Dream-enacting behaviours include agitation and physical activity during

sleep (e.g talking, yelling, punching, kicking and grabbing).

AUTONOMIC DYSFUNCTION

• Gastrointestinal disorder• Constipation• Urinary incontinence• Erectile dysfunction• Airway obstruction• Restrictive lung dysfunction

DIAGNOSIS

• Diagnosis at onset of PD is difficult with accurate diagnosis possible only with continued observation of evolving clinical signs and symptoms.

• There is no single definitive test or group test used to diagnose the disease.• The diagnosis is made on the basis of history and clinical examination.• A diagnosis of PD is typically made if at least two of the four cardinal features

are present.

HOEHN-YAHR CLASSIFICATION OF DISABILITY

Stage Character of Disability I Minimal or absent; unilateral if presentII Minimal bilateral or midline involvement. Balance not impairedIII Impaired righting reflexes.

Unsteadiness when turning or rising from chair.Some activites are restricted, but patient can live independently and continue some forms of employment.

IV All symptoms present and severe.Standing and walking possible only with assistance

V Confined to bed or wheelchair

An estimate of the stage and sverity of the disease

PHARMACOLOGICAL MANAGEMENT

• Levodopa (L-dopa). Nerve cells use l-dopa to make and replenish the brain’s supply of dopamine. L-dopa is often given along with carbidopa. Carbidopa delays the conversion of levdopa into dopamine until it reaches the brain. This prevents, or diminishes some of the side effects of L-dopa and reduces the amount of L-dopa needed. L-dopa delays the onset of debilitating symptoms and allows many patients to extend the period of time they are able to live “normal” lives. Bradykinesia and rigidity respond best and tremor may be only slightly reduced.• Bromocriptine, pergolide, pramipexole, and ropinirole. These drugs all mimic the role of dopamine in the brain.• Selegiline (deprenyl). This drug may delay the need of l-dopa therapy. When given with l-dopa, it seems to enhance and prolong the response of l-dopa.• Anticholinergics. These may help control tremor and rigidity. They appear to act by blocking the action of acetylcholine.• Amantadine. This is an antiviral drug. It is effective at reducing many symptoms, but its efficacy wears off after several months. Effectiveness may return after a brief withdrawal.

SURGICAL APPROACHES

• Implantation Transplanted fetal mesencephalic cells harvested from aborted foetuses, grown in cell culture and injected into the brain in a form of cell suspension, have been shown to survive in the brain and replace the production of dopamine. This surgery disabling dyskinetic movements.• Stereotatic surgery and implantation of stimulatorsThe target for the surgery is thalamus. This has this has been replaced by targeting either globus pallidus or more recently the STN. The target area of the brain may be lesioned to reduce its output to benefit the movement disorder or it may be stimulated in order to inhibit output with similar effect.

PHYSIOTHERAPY MANAGEMENT

• Physical activities to prevent muscle weakness, restricted ROM, reduced exercise capacity and social isolation.

• Assessment to monitor progress and jointly identify management priorities.• HEP training in the home and community setting• Modification of treatment and HEP to take account of levels of cognitive impairment,

medication, ageing and multiple pathology.• Provision of a forum such as regular group session to share information and identify

continuing needs of both individuals and carers.• Physical management to ensure co-ordination and integration of professional input

around patient centred goals.

RELAXATION EXERCISES

• Hook-lying, lower trunk rotation or side lying rolling can be used to promote relaxation.

• During therapy, slow, rhythmic, rotational movements of the extremities and trunk can precede interventions such as ROM, stretching and functional training.

FLEXIBILITY EXERCISE

• The purpose of flexibility exercise (stretching) is to improve ROM and physical function.

• A combination of PROM, AROM and PNF exercise is used to achieve maximum ROM.

• Flexibility exercise should be performed a minimum 2 to 3 days per week and a minimum of 4 repetitions per stretch for 15 to 60 seconds.

RESISTANCE TRAINING • Resistance training (strengthening) is indicated for muscle weakness.• Weakness of muscles associated poor posture and functional deficits.• Strengthening has been show to improve muscle force, bradykinesia

and quality of life in PD.• Starting with lower intensity than load can be applied using

resistance machines, free weights elastic resistance bands or manually.

• Strengthening can be performed 2days per week.

FUNCTIONAL TRAINING

• The exercise program should be based on focused practice of functional skills.

• Progression to more difficult motor activities should be gradual.• Bed mobility skills• Sitting• Sit-to-stand• Standing

BALANCE TRAINING

• Important focus of balance training is on COG centre of gravity and BOS base of support.

• Patients should be instructed how COG influences balance and how to improve posture in sitting and standing.

• Patient should also explore their BOS and practice working toward expanding them in sitting and standing.

• Balance training should emphasize practice of dynamic stability task (eg. Weight shifts, alternating unilateral weight-bearing, reaching and axial rotation of head and trunk)

• Seated activities can include sitting on a compliant surface (inflatable disc).

LOCOMOTOR TRAINING

• Locomotor training goals focus on reducing primary gait impairments, which typically include slowed speed, and shuffling gait pattern.

• Goals also focus on increasing patient’s ability to safely perform functional mobility activities and prevent falls.

• Large step and arm swing were more effective instructional strategies than the command to walk fast.

• Sidestepping and crossed-step walking also can be practiced.

SPINAL ORTHOTICS

• Spinal bracing may be an appropriate adjunct to therapy for patients with postural deformities.

• Thoracolumbar orthosis is not only corrects faulty posture but also has been shown to increase trunk stability and also increase respiratory vital capacity.

• When brace was use for 6month, 73%increase in back extensor strength and 58% increase in abdominal flexor strength.

PULMONARY REHABILITATION

• Diaphragmatic breathing exercises, air shifting techniques, exercise that recruit neck, shoulder and trunk muscles.

• Manual techniques such as vibration and shaking can be used to ensure complete exhalation, distal alveoli opening, and to assist with secretion clearance.

SPEECH THERAPY

• Lee Silverman Voice Treatment was designed specifically for PD patient.• It focus on intensive high-effort exercise with a single functionally relevant

target (loudness) and a recalibration of self-perception of vocal loudness.• This technique effectively increases vocal loudness and improves facial

expressions.

HOME EXERCISES PROGRAM

• HEP include exercises designed to improve relaxation, flexibility, strength and cardiopulmonary function.

• Early morning warm-up often helpful in reducing stiffness.• Stretching and strengthening exercises.• ROM exercises.• Balance activities.• HEP should be realistic and of moderate duration and intensity.