The video below is the section for Neurocognitive Disorder Due to Parkinson’s Disease from Part 2 of TSM’s lecture series on DSM-5 and the EPPP, followed by a transcript. This lecture series aims to equip those preparing for the EPPP with everything one needs to know about the impact DSM-5 will be having on the EPPP. To watch all of Part 2, click here. To watch Part 1, click here. To register for our webinar series to watch future lectures and discuss your questions with a content expert, click here.
Transcript of DSM-5 EPPP Lecture Video: Parkinson’s Disease
NARRATIVE DEFINITION: Parkinson’s Disease is a progressive neurological disorder caused by the degeneration of dopaminergic neurons within the substantia nigra, a subcortical area related to voluntary motor movement, and the nigrostriatal pathway, a neural tract heading to the striatum from the substantia nigra. The neurotransmitter dopamine is involved in the coordination of smooth and complex movement; dopamine deficits result in impaired motor activity. Severely decreased levels of dopamine in individuals with Parkinson’s Disease cause the disorder’s most characteristic symptoms: resting tremor, rigidity, bradykinesia (i.e., slowness), and postural instability.
Individuals with Parkinson’s Disease may find that while at rest, their hands, arms, or legs shake; these tremors often subside as the individual engages in purposeful movement. Early signs of muscle rigidity include a decreased arm swing while the person is walking, along with achiness and fatigue. As the disorder progresses, throat and facial muscles may weaken, causing the individual eventually to choke, cough, drool, and have difficulty swallowing. Rigidity in throat and facial muscles may also limit the range of vocal and facial expressions, causing people with Parkinson’s Disease to speak in a soft, monotonous voice and to display a vacant, mask-like facial expression.
Motor activity in individuals with this disorder is considerably slowed, particularly when they move from a resting state. Other motor abnormalities typically found include stooped posture, difficulty turning around, and gait disturbances characterized by small, shuffling steps.
As brain changes caused by Parkinson’s disease gradually spreads, they may begin to affect mental functions. Cognitive function are characteristically affected, with difficulty in memory, impairment in planning and making sound judgment. The prevalence of Parkinson’s disease increases with age, from about .5% between ages 65 and 69, to 3% at 85 years of older. The disease is more common in males than in females, and an estimated 75% of individuals affected will eventually develop serious cognitive problems (currently diagnosed as Major Neurocognitive Disorder, but still often referred to as dementia).
In the DSM-5, neurocognitive disorders are specified by the underlying or presumed cause. If the cause of the neurocognitive decline is believed to be Parkinson’s disease, a diagnosis of Parkinson’s Disease will be written first, followed by the diagnosis of Neurocognitive Disorder Probably Due to Parkinson’s Disease. If the etiology is not as certain, the diagnosis will be Neurocognitive Disorder Possibly Due to Parkinson’s Disease, and an additional code for Parkinson’s Disease will not be included.
All neurocognitive disorders are classified as either Major (when the cognitive decline from a previous level of performance was significant) or Minor (when the cognitive decline from a previous level of performance was modest). The diagnosis may also specify Without Behavioral Disturbance or With Behavioral Disturbance (e.g., psychotic symptoms, agitation, apathy). Severity specifiers indicate the overall level of functioning, describing whether the cognitive problems are Mild (difficulty is limited to instrumental activities of daily living, such as managing finances), Moderate (difficulty affects basic activities of daily living, such as feeding and dressing), or Severe (the person is fully dependent).
As many as half of all individuals with Parkinson’s Disease experience comorbid depressive symptoms, which can exacerbate symptoms. Research suggests that Depression does not always develop after Parkinson’s Disease, but may, in some individuals, precede other symptoms of the disorder. Indeed, according to the American Academy of Neurology (2007), in the year prior to a diagnosis of Parkinson’s Disease, individuals taking antidepressants were almost twice as likely to develop Parkinson’s Disease as were individuals who did not take antidepressants. This is not evidence that antidepressant use causes Parkinson’s Disease, but rather may suggest that Depression is an early symptom of the disease in some cases.
There is currently no cure for Parkinson’s Disease. The drug L-dopa may be administered to increase dopamine levels in the substantia nigra, thus controlling symptoms of the disease. However, L-dopa does not alleviate symptoms indefinitely and may cause unwanted physical and psychiatric side effects. Other medications may provide partial benefit. Surgeries to implant dopamine-containing cells are still controversial.
FLASHCARD: Parkinson’s Disease
- A progressive neurological disorder; linked to selective loss of dopamine-containing neurons in substantia nigra and nigrostriatal pathway
- Dopamine involved in the coordination of smooth and complex movement; dopamine deficits result in impaired motor activity
- Main symptoms: Resting tremor, motor slowness (bradykinesia), rigidity; postural instability, decreased voice volume, and mask-like facial expression may also result
- 20 percent to 60 percent of Parkinson’s patients will develop dementia: Cognitive slowing, impaired memory retrieval, and executive dysfunction. More likely to occur in older individuals, in advanced stages of the disease
- Depression also highly comorbid (up to 50 percent of cases; may follow initial motor symptoms or, in some cases, actually precede their display). Depression may exacerbate dementia
- In some individuals, depression precedes other symptoms of the disorder
- In the year prior to Parkinson diagnosis, individuals taking antidepressants almost twice as likely to develop Parkinson’s Disease as were individuals who did not take antidepressants; this may suggest that depression is an early symptom of the disease in some cases
- Onset typically after 65 years of age. Etiology unclear — could involve environmental toxins; heritability modest overall
- Dopamine agonists (L-dopa) and other medications may provide some symptomatic relief; no cure at present
Bradykinesia, resting tremors, gait disturbances, and depression are symptoms most commonly associated with:
A. Huntington’s Disease.
B. Parkinson’s Disease.
C. Alzheimer’s Disease.
D. Multiple Sclerosis.
RATIONALE: B is correct, as the question stem presents the core symptoms of Parkinson’s Disease. A is incorrect, as Huntington’s Disease is a progressive neurodegenerative genetic disorder, most notable in middle age, which affects muscle coordination and causes cognitive decline and dementia. Answer C is incorrect: Alzheimer’s Disease is a cortical dementia usually found in older adults and characterized by cognitive disturbances such as amnesia, aphasia, apraxia, agnosia, and diminished executive functioning. Answer D is also incorrect, as Multiple Sclerosis evidences changes in sensation, muscle weakness, difficulty in moving, problems with balance and coordination, difficulty in speech, visual problems, and fatigue.