Ans. c (Frontal lobe) (Ref. Harrison 18th/Fig 370-9).PARATONIA: | tone that varies irregularly in a manner that may seem related to a degree of relaxation, is present throughout the range of motion, affects flexors and extensors equally, usually results from lesion of bilateral frontal lobes or dominant frontal lobe.RIGIDITY: | Tone, affects flexors and extensors equally; seen in extrapyramidal lesionsSPASTICITY: | tone, affects mainly extensors and seen in pyramidal tract lesions.Signs and symptomsStructures involved# Paralysis of opposite foot and leg# A lesser degree of paresis of opposite arm# Cortical sensory loss over toes, foot, and legMotor leg areaArm area of cortex or fibers descending to corona radiateSensory area for foot and leg# Urinary incontinenceSensorimotor area in paracentral lobule# Contralateral grasp reflex, sucking reflex, gegenhaiten (paratonic rigidity)Medial surface of the posterior frontal lobe; likely supplemental motor area# Abulia (akinetic mutism), slowness, delay, intermittent interruption, lack of spontaneity, whispering, reflex distraction to sights and soundsUncertain localization--probably cingulate gyrus and medial inferior portion of frontal, parietaland temporal lobes# Impairment of gait and stance (gait apraxia)Frontal cortex near leg motor area# Dyspraxia of left limbs, tactile aphasia in left limbsCorpus callosumDeficit/feature of lesion of a particular area of brainLobesImportant regionsDeficit after lesionFrontalPrimary motor and premotorFrontal eye fieldsBroca speech area*Contralatera spastic paresis (region depends on area of homunculusEyes deviate to ipsilateral sideBroca aphasia (expressive, nonfluent aphasia): patient can understand written and spoken language, but speech and writing are slow and effortful; patients are aware of their problem; often associated with contralateral facial and arm weaknessPrefrontal cortexFrontal lobe syndrome: symptoms can include poor judgement, difficulty concentrating and problem solving, apathy, inappropriate social behaviorParietalPrimary somatosensory cortexSuperior parietal lobuleInfrerior parietal lobuleContralateral hemihypesthesia (region depends on area homunculus affected)Contralateral asteroegnosis and sensory neglect, apraxiaGerstmann syndrome (if dominant hemisphere): right/left: confusion, dyscalculia and dysgraphia, finger agnosia, contralateral hemianopia or lower quadrantanopiaTemporalPrimary auditory cortexBilateral damage deafnessUnilateral leads to slight hearing lossWernicke area*Wernicke aphasia (receptive, fluent aphasia); patient cannot understand any form of language; speech is fast and fluent, but not comprehensibleHippocampusAmygdalaOlfactory bulb, tract, primary cortexMeyer loop (visual radiations)Bilateral lesions lead to inability to consolidate short-term to long-termKluver-Bucy syndrome: hyperphagia, hypersexuality, visual agnosia Ipsilateral anosmiaContralateral upper quadrantanopia ("pie in the sky")OccipitalPrimary visual cortexBlindnessAlso Remember: Parietal lobe lesions | | | Dominant lobe Non dominant lobe | | Multinodal complex motor activities affected Multinodal complex sensory disabilities | | # Ideational# Ideomotor# Alexia}Apraxia Visuospatial disorders(Hemiattention) AnosognosiaDressing and constructionalApraxia# Gerstamann's syndrome