Lesions of inferior frontal gyrus of the dominant hemisphere will manifest as the following in patients -
Ans. is 'a' i.e., Brocas aphasia [Ref: Harrisons 18th/ep. 203-4, internet)* Patient has normal comprehension but speaks with short utterances of a few words at a time, comprised mostly of nouns. These findings are suggestive of brocas aphsia. It is seen in patients having affection of the inferior frontal gyrus of the dominant hemisphere. The patient is right handed so the left hemisphere, will the dominant one. Thus most probable location of the lesion is left inferior frontal gyrus.Inferior Frontal Gyrus* The inferior frontal gyrus is a part of the frontal gyrus of the frontal lobe.* The inferior frontal gyrus includes the following cytoarchitectonic areas of brain:i) Brodmann area 44ii) Brodmann area 45iii) Brodmann area 47* Brodmann area 44 corresponds to Broca's area (sometimes Broca's area is taken to encompass Brodmann's areas 44 and 45) -- for the dominant hemisphere of the brain.* The left inferior frontal gyrus (IFG) is extremely important for language comprehension and production due to the fact that most language processing takes place in the left hemisphere. Commonly known as "Broca's area",persons with damage in this region often have a type of non-fluent aphasia known as Broca's aphasia.* Broca's area is located on the left/ dominant hemisphere of the brain and encompasses Brodmann's area 44 and 45.* Area 44 is involved in the language production and phonological processing due to its connections with motor areas like the mouth and tongue.* Area 45 is a part of the anterior inferior frontal gyrus and is involved in semantic processing.* Characteristics of Broca's aphasia include agrammatic speech, relatively good language comprehension, poor repetition, and difficulty speaking.* Persons with Broca's aphasia do not have deficits in language comprehension; however, they speak mostly in short utterances of a few words at a time, comprised mostly of nouns.* Their speech is limited to short sentences, and producing sound is a very difficult task for those affected.* Thus lesions of the dominant hemisphere of the inferior frontal gyrus tend to present as Brocas aphasia.Clinical features of aphasias and related cnditions ComprehensionRepetition of spoken languageNamingFluencyWernickesImpairedImpairedImpairedPreserved or increasedBrocasPreserved (except grammar)ImpairedImpairedDecreasedGlobal ImpairedImpairedDecreasedConductionPreservedImpairedImpairedPreservedNonfluent (motor) transcorticalPreservedPreservedImpairedImpairedFluent (sensory) transcorticalImpairedPreservedImpairedPreservedIsolationImpairedEcholaliaImpairedNo puposeful speechAnomicPreservedPreservedImpairedPreserved except for word-finding pausesPure word deafnessImpaired only for spoken languageImpairedPreservedPreservedPure alexiaImpaired only for readingPreservedPreservedPreserved
Brocas aphasia
Wernickes aphasia
Anomia
Pure alexia
C.N.S.