Personality Change Flashcards
Assessing level of consciousness in a patient assesses the function of. . .
. . . the reticular activating system and ascending projections. BUT, can also indicate bilateral thalamic involvement or diffuse involvement (such as in intracranial hypertension or subdural hemorrhage)
“Lethargic” patient
Falls asleep without repeated stimulation
“Stuporous” patient
Requires vigorous and/or painful physical stimulation to be awakened
Think Prince Ivan
“Obtunded” patient
Somewhere between lethargic and stuporous
Differences between different clinical tests for attention
Note that the spelling task requires language ability and the subtraction task requires calculation, so forward and backward repetition of a string of numbers of increasing length provided by the examiner or recitation of the days of the week (or months of the year) backward may be simpler and less confounded ways of testing attention.
Even patients with the most profound deficits in memory due to neurologic conditions should never forget ___
Even patients with the most profound deficits in memory due to neurologic conditions should never forget their own names
Time course of dementia vs “rapidly progressive” dementia
Dementia is a chronic disease that develops over years
Rapidly progressive dementia develops over weeks to months
Frontal release signs (list)
- Snout reflex: the patient purses the lips when the examiner taps at the center of the lips.
- Grasp reflex: the patient cannot inhibit grasping the examiner’s hand or an object when placed into the patient’s hand.
- Suck reflex: the patient will attempt to suck any object (such as a pen) moved toward the mouth.
- Rooting reflex: lightly touching the patient’s cheek causes the patient to turn the head toward that side.
- Palmomental reflex: briskly scratching the patient’s palm causes a twitch of the ipsilateral chin.
Laboratory evaluation for dementia
- B12
- TSH
- MRI
Alzheimer’s disease
- Most common neurodegenerative cause of dementia
- Most cases sporadic, some familial
- Heritable form due to amyloid precursor protein, presenilin 1, presenilin 2 variants that predispose to amyloid plaque buildup - younger age of onset
- APP is on chromosome 21, so Down’s patients also at increased risk
- Episodic memory first and most prominently affected
- Other common traits at presentation include getting lost, decreased performance at work, and word retrieval difficulty.
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Posterior cortical atrophy
- A variant of Alzheimer’s disease where neurodegeneration occurs specifically in parieto-occipital regions
- Leads to visual cognitive deficits, specifically Balint’s syndrome
- Can also occur with other neurodegenerative diseases, but most commonly we see it in AD.
Neuroimaging Features of Alzheimer’s Disease
- MRI in AD usually demonstrates bilateral atrophy in medial temporal regions (hippocampus and entorhinal cortex) and the superior parietal lobe
- Image: Axial MRI images showing marked bilateral hippocampal atrophy (A) and bilateral parietal more so than frontal cortical atrophy (B) in a patient with Alzheimer’s disease.
ABSEPTIC mnemonic
Entorhinal cortex
An area of the brain located in the medial temporal lobe and functions as a hub in a widespread network for memory, navigation and the perception of time. The EC is the main interface between the hippocampus and neocortex.
Laboratory Features of Alzheimer’s Disease
- In the cerebrospinal fluid (CSF), low Aβ42 and increased tau (leading to decreased Aβ42/tau ratio) can predict underlying Alzheimer pathology in the appropriate clinical setting.
- Amyloid is presumably low in the CSF because it has accumulated in plaques in the brain.
Treatment of Alzheimer’s disease
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Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and the N-methyl-d-aspartate (NMDA) antagonist memantine may provide modest symptomatic benefit in cognition in patients with AD.
- Gastrointestinal side effects can occur with the cholinesterase inhibitors.
- A common treatment strategy in patients with AD is to use a cholinesterase inhibitor initially (if tolerated), and to add memantine as patients progress to moderate/severe dementia.
- Otherwise, care of patients with AD is supportive.
Dementia With Lewy Bodies
- One of the Parkinson’s Plus syndromes
- Parkinsonian symptoms go along with dementia
- Dementia characterized by initial deficits in visuospatial and executive function, in tandem with parkinsonian hypokinesia and REM sleep abnormalities
- Later may develop visual hallucinations, fluctuations in attention and level of arousal
- Neuroleptic sensitivity (worsened parkinsonism and/or cognition with administration of neuroleptics) and autonomic dysfunction (orthostasis, constipation, incontinence, sexual dysfunction) are frequently present
Distinguishing Dementia with Lewy Bodies from pure Parkinson’s with dementia
- Patients with DLB develop symptoms and signs of dementia before or simultaneously with features of parkinsonism
- In Parkinson’s disease dementia, parkinsonism usually precedes dementia by years
- Parkinsonism in DLB is usually symmetric (in Parkinson’s disease, parkinsonism usually begins asymmetrically)
- Parkinsonism in DLB is usually less responsive to levodopa (or may not respond at all) compared to patients with Parkinson’s disease (whose parkinsonism generally responds to levodopa).
Neuroimaging Features of Dementia With Lewy Bodies
There is no characteristic pattern of atrophy on structural imaging in DLB, but nuclear imaging may show hypometabolism/hypoperfusion in occipital and temporoparietal regions (especially along the sylvian fissure) (compared to just temporoparietal hypometabolism/hypoperfusion in AD).
DLB vs AB on MRI (with a normal control)
Treatment of Dementia With Lewy Bodies
- As in AD, cholinesterase inhibitors and memantine may be useful in symptomatic management of cognitive dysfunction in DLB.
- As in the other Parkinson-plus syndromes, there is usually little or no response to dopaminergic therapies (in contrast to Parkinson’s disease), but if parkinsonism is a prominent disabling feature in a patient with DLB, a trial of levodopa can be considered.
- Symptomatic treatment can be considered for mood, REM sleep behavior disorder (clonazepam), and autonomic dysfunction.
Drug of choice for treating REM sleep dysfunction in Parkinson’s and Parkinson’s-Plus syndromes
Clonazepam
A benzodiazepine highly effective for RBD
Frontotemporal Dementia
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Includes two categories of dementia syndromes: behavioral variant FTD (bvFTD) and primary progressive aphasia (PPA).
- bvFTD is characterized by personality changes and neuropsychiatric dysfunction (might be apathy, disinhibition, social withdrawal, social deviant behavior, etc. Very broad range)
- Clinical insight typically poor
- Other common features include loss of empathy, obsessive compulsive or perseverative behaviors, and executive dysfunction
- PPA is characterized by language deficits
- three variants with particular language deficits: nonfluent/agrammatic, semantic, and logopenic
- bvFTD is characterized by personality changes and neuropsychiatric dysfunction (might be apathy, disinhibition, social withdrawal, social deviant behavior, etc. Very broad range)
Neuroimaging in frontotemporal dementia
- Neuroimaging in FTD shows selective frontotemporal atrophy that may be very focal within language areas in PPA.
- Images: Sagittal (A) and axial (B) T1-weighted images demonstrating marked left frontotemporal atrophy. Note the widening of the insula (A) and the “knife edge” atrophy of the left temporal lobe (B).
Unlike focal tumors of the brain, diffuse infiltrative lesions or diffuse metastases can present with . . .
. . . global cognitive dysfunction and/or personality changes without obvious focal deficits
Syndrome of hearing loss, tinnitus, imbalance. Where is the tumor and what type of tumor is it likely to be?
cerebellopontine angle tumor
most commonly vestibular schwannoma or meningioma
Syndrome of bitemporal hemianopia. Where is the tumor and what type of tumor is it likely to be?
At the optic chiasm
Pituitary tumors or craniopharyngioma are most common
Syndrome of visual disturbance. Where is the tumor and what type of tumor is it likely to be?
Anterior to the optic chiasm
optic glioma, optic nerve sheath meningioma, or olfactory groove meningioma(olfactory groove meningioma may also cause unilateral loss of smell)
Syndrome of multiple cranial neuropathies. Where is the tumor and what type of tumor is it likely to be?
skull base lesion, brainstem lesion, or leptomeningeal metastases
Can be caused by wide variety of tumors, often metastatic in origin
MRI of leptomeningeal metastasis
- Contrast-enhanced brain imaging reveals enhancement of the leptomeninges, which can be noted in the cerebellar folia, surrounding the brainstem, and invaginating the cerebral sulci
- Hydrocephalus may also be present.
- Normal MRI does not exclude the possibility of leptomeningeal metastases! Definitive diagnosis is made by CSF cytology and flow
Meningiomas
- Dural based lesions that enhance uniformly on contrast-enhanced neuroimaging and often have a dural tail of enhancement at the margins of the tumor
- Treatment of meningiomas is surgical.
- Postoperative radiation therapy is used for grade 3 (anaplastic) meningiomas and incompletely resected grade 2 (atypical) meningiomas
- Radiation therapy without surgery may be considered for patients whose meningiomas are inoperable, or in patients who are not good surgical candidates.
- Incidentally discovered meningiomas can generally be followed with serial imaging if they are small and asymptomatic.
What type of tumor is shown?
Glioma, low grade
What type of tumor is shown?
Glioma, specifically gliomatosis cerebri
What type of tumor is shown?
Glioblastoma, high grade
What type of tumor is shown?
Primary CNS lymphoma, likely diffuse large B cell lymphoma
Most common benign and malignant tumors in adult and pediatric cases of brain cancer
A brain tumor within the cerebral cortex is biopsied. Based on histologic appearance and location, what type of tumor is this?
Oligodendroglioma
Has a characteristic “fried egg” appearance
A brain tumor pressing up against the posterior cerebellum, in the posterior fossa, is biopsied from a 7 year old child with cerebellar symptoms. Based on histologic appearance and location, what type of tumor is this?
Medulloblastoma
You can tell by the characteristic “Homer-Wright Rosettes” made by the nuclei and bare cytoplasmic spaces.
A brain tumor pressing up against the posterior cerebellum, in the posterior fossa, is biopsied from a 7 year old child with cerebellar symptoms. Based on histologic appearance and location, what type of tumor is this?
Ependymoma
You can tell by the perivascular rosettes, surrounding the blood vessels.
Pineal gland tumors and Parinaud syndrome
- Parinaud syndrome is caused by pineal tumors or other tumors that compress the dorsal midbrain and superior colliculus
- Parinaud syndrome is characterized by: Impaired vertical gaze, impaired pupillary light reflex, and convervence retraction nystagmus (in other words, the eyes appear to jerk backwards into the orbit when the patient attempts to look up)
What is going on in this MRI?
Sagittal (A) and axial (B) T1-weighted images demonstrating marked left frontotemporal atrophy. Note the widening of the insula (A) and the “knife edge” atrophy of the left temporal lobe (B).
Dementia summary table
