Cortical disorders Notes

NOTES NOTES CORTICAL DISORDERS GENERALLY, WHAT ARE THEY? PATHOLOGY & CAUSES ▪ Cortical structure damage in brain → functional regional-specific impairment CAUSES ▪ Stroke (common), hemorrhage, infection, tumor, trauma, surgery, degenerative disease (e.g. Broca’s aphasia, Wernicke’s aphasia, Klüver–Bucy syndrome) SIGNS & SYMPTOMS ▪ Affected brain region dependent ▪ Broca’s aphasia ▫ Expressive nonfluent aphasia ▪ Wernicke’s aphasia ▫ Receptive fluent aphasia ▪ Klüver–Bucy syndrome ▫ Amnesia, compulsive eating, hypersexuality DIAGNOSIS DIAGNOSTIC IMAGING ▪ CT scan, MRI, single-photon emission computerized tomography (SPECT), positron emission tomography (PET) LAB RESULTS ▪ Cerebrospinal fluid (CSF) analysis OTHER DIAGNOSTICS ▪ Functional assessment ▪ Neurological exam TREATMENT OTHER INTERVENTIONS ▪ Address underlying cause MNEMONIC: MD vs. DPM Cortical brain Memory Discrimination Subcortical brain Devoid of seizure Primary sensation through thalamus Movement disorders (most) OSMOSIS.ORG 547

BROCA'S APHASIA osms.it/brocas-aphasia PATHOLOGY & CAUSES ▪ Aphasia ▫ Language loss/defect (speaking, fluency, reading, writing, comprehension) ▫ Injury to brain’s language centers → different aphasia types ▫ Most lesions involve dominant hemisphere (left in 95% of right-handed individuals, right in 50% of left-handed individuals) ▪ Broca’s aphasia ▫ Broca’s area: responsible for language comprehension ▫ Damage to Broca’s area → expressive nonfluent aphasia (trouble expressing language → “individuals know what they want to say, but cannot get it out”) CAUSES ▪ Stroke (superior division of left-middle cerebral artery), traumatic brain injury, brain tumor, cerebral hemorrhage SIGNS & SYMPTOMS ▪ Slowed, effortful speech ▪ Short sentences without grammatical construction (content appropriate, meaningful) ▪ Individual with Broca’s aphasia may describe trip to barber for haircut as follows ▫ “Yes... errr... Tuesday... er... Dad and Kevin T... (his own name), and Dad.... er... the mall... and ah... Tuesday... Tuesday, ten o’clock... and.. oh barber... one... um’ barber... and er... hair...” ▪ Written, spoken language comprehension intact (or mildly impaired) ▪ Self-monitoring speech (generally still capable) → awareness of speech deficit 548 OSMOSIS.ORG ▪ Broca’s area: anterior to primary motor cortex, damage to adjacent areas → individual may have associated contralateral hemiparesis, hemisensory loss DIAGNOSIS DIAGNOSTIC IMAGING ▪ Findings vary by underlying aphasia cause ▫ May include evidence of bleeding/ hypodensities (stroke); mass effect, overt tumors (cancer) ▫ Functional imaging will reveal regional perfusion deficits Brain CT scan ▪ With/without contrast MRI ▪ Standard MRI ▪ Diffusion tensor imaging (images white matter tracts) ▪ Functional MRI (images neurological activity) SPECT/PET ▪ Images neurological activity OTHER DIAGNOSTICS ▪ Language assessment, screening tools TREATMENT ▪ Treat underlying cause ▪ Most individuals improve/recover spontaneously within one month OTHER INTERVENTIONS ▪ Speech therapy (early initiation)

Chapter 70 Cortical Disorders KLÜVER–BUCY SYNDROME osms.it/kluver-Bucy_syndrome PATHOLOGY & CAUSES ▪ AKA bilateral temporal lobe disorder ▪ Caused by bilateral lesions to medial temporal lobe ▫ Hippocampus, surrounding structures including amygdala; vital for declarative, long-term memory CAUSES ▪ Trauma/lobectomy, herpes simplex encephalitis, stroke, Pick's disease, Alzheimer’s disease SIGNS & SYMPTOMS ▪ Amnesia (profound antero-, retrograde amnesia), inappropriate things/compulsive eating, inappropriate object insertion into mouth, hypersexuality, visual agnosia (inability to recognize familiar objects/ people), docility (diminished fear/aggression response) DIAGNOSIS ▪ Three/more symptoms present (most commonly placidity, hyperorality, dietary changes) DIAGNOSTIC IMAGING CT scan/MRI ▪ Temporal lobe lesions LAB RESULTS ▪ If viral encephalitis underlying cause → CSF analysis, serology ▪ CSF fluid analysis ▫ Normal/mild protein ↑, normal/low glucose content, normal/raised red cell count, lymphocytosis ▪ CSF serology ▫ CSF antibodies compared to serumspecific antibodies ▫ 4x rise in virus specific IgG/positive IgM ▪ CSF polymerase chain reaction (PCR) → specific virus identification TREATMENT MEDICATIONS ▪ Herpes simplex encephalopathy → antivirals OSMOSIS.ORG 549

WERNICKE'S APHASIA osms.it/wernickes-aphasia PATHOLOGY & CAUSES ▪ Wernicke’s aphasia ▫ Wernicke’s area: assigns speech sounds meaning ▫ Damage to Wernicke’s area → receptive, fluent aphasia (trouble interpreting language) CAUSES ▪ Typically stroke (left middle cerebral artery), traumatic brain injury, brain tumor, cerebral hemorrhage SIGNS & SYMPTOMS ▪ Impaired written, spoken language comprehension ▪ Unaware of speech error, meaninglessness ▪ Speech-specific symptoms ▪ Jargon: neologisms, real words used meaninglessly; structurally intact speech, typical intonation but lacks content ▫ Literal (phonemic) paraphasia: substitution, addition, rearrangement of sounds → errors sound like intended word( e.g. “nog” instead of “dog”) ▫ Verbal (semantic) paraphasia: related word instead of intended word (e.g “spoon” instead of “fork”) ▫ Neologism: made-up non-word instead of intended word (e.g. “fluparp” for “kettle”) ▫ Circumlocution: describe intended word (e.g. “it’s pointed, thin, you write with it”, in reference to a pen) ▫ Run-on speech: verbalized idea stream related to topic (e.g. asked what do you do at the pet store: “The pet store is a place, it is a place with many pets, and pet food, my favourite animals are dogs, at the pet store I buy food for my dog, there are also fish at the pet store…”) 550 OSMOSIS.ORG DIAGNOSIS DIAGNOSTIC IMAGING ▪ Findings vary by aphasia cause ▫ May include evidence of bleeding/ hypodensities (stroke); mass effect, tumor (cancer) ▫ Functional imaging reveals regional perfusion deficits Brain CT scan ▪ Vary by aphasia cause ▪ With/without contrast MRI ▪ Vary by aphasia cause ▪ Standard MRI ▪ Diffusion tensor imaging ▪ Functional MRI SPECT/PET ▪ Vary by aphasia cause OTHER DIAGNOSTICS ▪ Language assessment, screening tools TREATMENT OTHER INTERVENTIONS ▪ Most individuals improve/recover spontaneously within one month ▪ Speech, comprehension therapy (early initiation)

Chapter 70 Cortical Disorders OSMOSIS.ORG 551