Focal brain syndromes in neuropsychiatry

Question 1

What are some of the symptoms of classic dysexecutive syndrome?

Answer 1

• inability to plan or organise, problems generating new ideas, difficulty thinking in an abstract way
  -unconcerned for past/future consequences of action
• ‘environmental dependency syndrome’, or ‘forced utilisation’ behaviour (relying on environmental cues to accomplish task)

Question 1

what do lesions in the dorsolateral prefrontal cortex (DLPFC) lead to?

Answer 1

classic dysexecutive syndrome.

Question 2

what do lesions in the Orbital prefrontal cortex lead to ?

Answer 2

disinhibition, restlessness, impulsiveness, perseveration, aggression, euphoria, imitation, utilization, compulsive behavior, inappropriate social behavior, impaired empathy, and impaired theory of mind.

Question 3

what are some of the causes of lesions in the dorsolateral prefrontal cortex?

Answer 3

tumours, cerebrovascular accidents and frontal neurodegeneration.

Question 4

what is ‘frontal lobe paradox?

Answer 4

patients with dramatic behavioural and executive ‘real world’ difficulties perform normally on cognitive testing.

Question 5

What are some of the causes of lesions in the orbital prefrontal cortex?

Answer 5

frontal tumours, multiple sclerosis, frontal neurodegeneration, and anterior cerebral artery CVA.

Question 6

What are the symptoms of disturbance/lesions in the medial prefrontal cortex ?

Answer 6

apathy and loss of initiative, diminished motor activity, general and emotional indifference, reduced social interest, impaired problem solving, loss of engagement with activities of daily living, hyperorality, and loss of insight.

Question 7

what are some causes of disturbance/lesions in the medial prefrontal cortex ?

Answer 7

hydrocephalus, bilateral anterior cerebral artery occlusion and tumours of the thalamus, 3rd ventricle, hypothalamus and pituitary

Question 8

what are some of the tests of frontal lobe function?

Answer 8

• Luria’s motor sequencing: - Ability to perform and organise rapid sequence motor tasks
• Desk tap test for cognitive flexibility
  Similarities / differences. Test of abstract reasoning
  -Cognitive estimate- frontal lobe lesions have difficulty producing accurate estimates.
  -Stroop test. This tests response inhibition, particularly impaired in orbitofrontal lesions
  -Verbal fluency, eg, list words starting with letter S
  -Proverb interpretation

Question 9

What is the role of the parietal lobe?

Answer 9

integral to the perception of external space and body image.

Question 10

what are the symptoms of Non-dominant parietal lesions ?

Answer 10

• disturbed body image and impaired sense of position in external space
  -anosognosia/anosodiaphoria towards the disability.
• Left sided limbs cannot be recognised or are entirely disowned (asomatognosia).
  -Dyscalculia
  -Neglect of the left side

Question 11

Where does the non-dominant lesion occur in the parietal lobe? (left or right )

Answer 11

right

Question 12

what are the symptoms of dominant parietal lobe lesions?

Answer 12

• dysphasia- patient speaks slowly, makes grammatical errors and may be mistakenly labelled as confused or uncooperative.
• ‘agnosia
• Astereoagnosia-patient cannot name (with eyes closed) a familiar object held in the hand based on the weight and three-dimensional characteristics
• Agraphesthesia numbers or letters written on the patients skin may not be recognised by touch

Question 13

What are some neurological features of parietal lobe lesions?

Answer 13

-Cortical sensory loss
-impaired sensory localisation
-sensory and visual inattention.
- A mild contralateral hemiparesis is seen. There may also be a contralateral homonymous lower quadrantopia.

Question 14

where would the lesions of Primary motor and sensory dysphasia be in the parietal lobe?

Answer 14

Primary motor dysphasia= anterior lesions
Primary sensory dysphasia= posterior lesions.

Question 18

what are some of the Clinical tests of parietal lobe function?

Answer 18

-Drawing a clock face
-Recognition of familiar object in hand (with eyes closed)
-Reading – if neglect, may ignore the left side of the page
-Writing
-Arithmetic
-Dressing – look for apraxia
-Neurological examination
-Visual field examination

Question 19

what are some of the roles of the temporal lobe?

Answer 19

-stimulation of the temporal lobes can elicit complex perceptions, memories and experiences
-Déjà vu
-Auditory, gustatory and visual hallucinations

Question 20

what are some of the symptoms of dominant lesions in temporal lobe??

Answer 20

• language problems
  -Receptive dysphasia, Wernicke’s aphasia
• Expressive speech can become hyperfluent with nonsense words.
• difficulty with repetition

Question 21

what are some of the symptoms of non-dominant lesions in the temporal lobe??

Answer 21

• Prosopagnosia ( inability to recognise faces)
  Receptive aprosody -cannot comprehend other’s intonation and may misinterpret non-verbal social communication.
• fail to recognise familiar voices (phonagnosia).

Question 22

what are some of the symptoms of temporal lobe epilepsy?

Answer 22

fear,
anxiety,
pleasure,
depersonalisation,
depression,
déjà vu (familiarity) and jamais vu (unfamiliarity).

Question 23

what can epileptic seizures originating from the temporal lobe lead to ?

Answer 23

• aphasia, auditory, visual and vestibular disturbances.
  -Oral automatisms are also common.

Question 24

what are Bilateral hippocampal lesions and where does it occur?

Answer 24

• it occurs in the temporal lobe.
• severe amnestic syndromes. Inability to store and recall new information

Question 25

what is Kluver-Bucy syndrome?

Answer 25

• caused by bilateral medial temporal lobe lesions. It is characterised by placidity, hypersexuality, hyperorality, altered sexual behaviour, visual agnosia, hypermetamorphosis (compulsive exploration of environment) and a failure to learn from aversive stimuli.
• this lesion can be caused by Alzheimer’s disease, carbon monoxide poisoning, frontotemporal dementia, head injury, herpes encephalitis, temporal lobe stroke, temporal lobectomy and temporal lobe tumour.

Question 26

what are some of the clinical test for temporal lobe function ?

Answer 26

-Speech comprehension (test for receptive aphasia and aprosodia)
-Word / sentence repetition (test for conduction aphasia)
-Writing/Reading ability
-Rey–Osterrieth Complex Figure Test (ROCF) - test for memory

Question 27

what are some of the roles of the occipital lobe ?

Answer 27

• higher order visual processing.
• Process complex information about the form, motion, colour and depth of perceived objects.

Question 28

what do lesions in the primary visual cortex lead to?

Answer 28

visual blind spots (scotomas) and partial blind spots (amblyopias) in the contralateral visual field.

Question 29

what do lesions in the bilateral occipital cortex lead to ?

Answer 29

• visual agnosia, patients cannot recognise an object that is presented visually. The object can be seen but not named. It will be recognisable by the patient on description or touch.
• Prosopagnosia is the inability to recognise faces. It is due to disconnection of the inferior visual association cortex from the non-dominant temporal cortex (so lesions to either may be causative).
• autoprosopagnosia (inability to recognise self in a mirror).

Question 30

what is Bálint syndrome and what is it casued by ? us

Answer 30

• caused by bilateral occipital lesions
• inability to perceive the visual field as a whole (simultanagnosia),
• difficulty in fixating the eyes (oculomotor apraxia)
  -inability to move the hand to a specific object by using vision (optic ataxia).

Question 31

what is cortical blindness/ blind sight ?

Answer 31

sense nearby objects or even discriminate facial expressions but cannot see due to lesions in occipital lobe

Question 32

what is Charcot-Wilbrand syndrome,

Answer 32

the loss of ability to create any mental visual images

Question 33

what is Posterior cortical atrophy (PCA)?

Answer 33

neurodegenerative syndrome dominated by deterioration of higher visual function (particularly visuospatial and visuoperceptual abilities) as the pathology predominantly affects the occipital lobe.

Question 34

how to test for the occipital lobe ?

Answer 34

Visual field testing including detection of object movement
Naming of familiar objects, colours
Reading ability
Interpretation and description ‘overall meaning’ of a complex visual image (test for simultagnosia)

Question 35

what does damage to corpus callosum lead to ?

Answer 35

left ideomotor apraxia, right or bilateral constructional apraxia, left agraphia, alexia in the left visual field and astereognosis in the left hand. Mutism may also occur.

Question 36

what do lesions in the thalamus result to ?

Answer 36

sensory disturbances such as those seen in parietal lobe lesions. In addition there may be hyperalgesia or analgesia.

Question 37

What does the basal ganglia include ?

Answer 37

caudate, putamen, globus pallidus, substantia nigra, ventral tegmental area, pedunculopontine tegmental nucleus and subthalamic nucleus

Question 38

what is the role of the basal ganglia ?

Answer 38

• release of inhibition, hence lesions result in release of behaviour (e.g. uncontrolled movement of Parkinson’s
• The ventral striatum contains the nucleus accumbens, implicated in goal-directed behaviour and the rewarding effects of carbohydrates and drugs of abuse.

Question 39

what is Pantothenate kinase-associated neurodegeneration (PKAN) and how is it caused ?

Answer 39

• caused by lesions in the basal ganglia
• an autosomal recessive disorder leading to parkinsonism, dystonia, dementia, and ultimately death

Question 40

symptoms of lesions/disturbance in the cerebellum

Answer 40

• problems with executive function, spatial cognition, language and affect.
• Personality changes presenting with blunting of affect or disinhibition.

Question 41

symptoms of lesions in the brainstem, specifically the raphe nuclei

Answer 41

• pathological crying
• Ventral pons injuries can result in locked-in syndrome, characterized by paralysis of all four limbs and paralytic mutism