#brain lesion

• Acalculia — A clinical neurological or neuropsychological deficit characterized by the acquired loss of the ability to perform simple arithmetic operations or to understand fundamental mathematical concepts, typically occurring due to an organic brain injury (usually affecting the left parietal lobe). Unlike dyscalculia, which is a congenital developmental disorder, achalusia represents a cognitive impairment secondary to trauma, stroke, or neurodegenerative processes.
• Acataphasia — A severe neuropsychological speech disorder characterized by the patient's inability to formulate syntactically and grammatically correct sentences, whereas the ability to pronounce isolated words and the comprehension of their meaning remain intact. This symptom typically arises from focal brain lesions or specific neurodegenerative conditions, leading to fragmented, agrammatic, and incoherent expression.
• Achromatognosia — A rare neurological disorder (gnosic) characterized by the patient's inability to recognize, identify, or name colors, even though their peripheral visual system, retina, and optic nerve are structurally intact. This condition is usually caused by lesions located in the occipito-temporal cerebral cortex (associative visual area) and often manifests within visual agnosia.
• Aphasia — A severe communication disorder consisting of the total or partial loss of the ability to speak, write, and understand articulate or written language, occurring in the absence of sensory deficits or vocal apparatus impairment. It is triggered by acquired organic lesions in the cerebral cortex, primarily affecting the language-dominant hemisphere.
• Aphimia — A specific form of motor aphasia characterized by the loss of the ability to execute the articulated movements required for speech, while comprehension and the peripheral vocal apparatus remain intact. In clinical neurology, aphimia is caused by focal lesions in the left frontal lobe.
• Agnosia — A neurological disorder characterized by an inability to recognize or interpret sensory impressions, such as objects, persons, sounds, or shapes, despite intact primary sensory organs and general intellectual functioning; it typically results from structural damage to the associative cerebral cortex.
• Agraphia — A neurological disorder characterized by the partial or complete loss of the ability to write, resulting from acquired brain damage to the dominant hemisphere, unrelated to motor paralysis of the hand or general intellectual impairment.
• Agrammatism — A neurological language disorder commonly associated with Broca's aphasia, characterized by the loss of the ability to produce grammatically correct sentences; patients exhibit a telegraphic speech style, omitting functional words such as prepositions, articles, and conjunctions.
• Alexic — Pertaining to alexia, belonging to alexia, or affected by this neurological disorder; a person who has lost the ability to read and decode written language due to a cortical brain lesion. In medical semiology, the term characterizes the cognitive behavior or specific deficits within a complex aphasic syndrome, where the recognition of symbolic graphic signs is completely compromised.
• Alexic — The feminine form for alexic, designating a female patient or person affected by alexia (loss of reading ability due to a brain lesion); also, it describes a manifestation, disorder, or pathological state presenting the characteristics of alexia, marked by the impossibility of decoding written graphic signs.
• Alexia — A severe neurological disorder characterized by the total or partial loss of the ability to read and comprehend written language, caused by an acquired lesion in the brain structures involved in visual-linguistic processing (specifically in the left parietal or occipital lobe). Unlike illiteracy, the condition occurs in individuals who previously possessed the ability to read, and unlike dyslexia, it is an acquired condition rather than a developmental disorder.
• The alexias — The definite articulated feminine plural form of the noun alexia, designating collectively and specifically all the types, manifestations, or identified clinical cases of loss of the ability to read and comprehend written text due to a cortical brain lesion. In medical literature, the term individualizes the forms of word blindness studied within a specific patient group or nosological framework.
• Alexia — An extremely rare specialized medical term used to describe the pathological inability or severe difficulty to read or understand written text, often conceptually correlated with alexia or agraphia; by extension, in some old psychopathology papers, the term indicates a focal neurological disorder resulting from a brain lesion in the left parietal or occipital lobe, affecting the symbolic processing of graphic signs without altering visual acuity.
• Allocheiria — A graphic and clinical variant of the term 'allocheiria'; it represents a neurological disorder of somatic sensitivity where a patient localizes a tactile, thermal, or painful stimulus on the opposite side of where it was actually applied. This structural phenomenon reflects a severe dysfunction in signal transmission and processing within the secondary somatosensory cortex or the parietal lobe, often associated with hemispatial neglect.
• Allophasia — A language or speech disorder characterized by the utterance of incoherent, inappropriate words or phrases that are completely different from those the patient structurally intends to express. This pathological condition typically appears as a symptom in sensory aphasias, severe mental confusion states, or following focal lesions in the dominant cerebral hemispheres, disrupting communication coherence.
• Amorphognosia — A cognitive neurological disorder of the agnostic type, consisting of the patient's inability to recognize, through tactile palpation, the general shape or geometric dimensions of objects, in the absence of elementary skin sensory deficiencies. This structural defect indicates a focused lesion within the contralateral parietal lobe of the cerebral cortex.
• Amusia — A congenital or acquired neurological disorder (following a brain injury) characterized by the partial or total inability to recognize, hum, reproduce, or understand musical tones, rhythm, and melodies, despite biological hearing and general intellectual functions remaining perfectly intact; tone deafness. This structural phenomenon affects the cognitive processing of sound structures in the secondary auditory cortex.
• Anarthria — An extreme clinical form of dysarthria, characterized by the complete loss of the ability to articulate words and pronounce speech sounds, resulting from a severe lesion of the central or peripheral nervous system (such as strokes, head traumas, or neurodegenerative diseases). In neurological semiology, this structural disorder exclusively affects the motor function of the muscles involved in phonation, while language comprehension and writing capabilities remain intact.
• Anozodiaphoria — A neuropsychological disorder characterized by a state of affective indifference or complete unconcern displayed by a patient toward the presence of a severe functional deficit, such as a paralysis (hemiplegia) resulting from a stroke. Although the patient can verbally acknowledge the physical problem (unlike in anosognosia), they exhibit a bizarre lack of worry or emotional reaction toward the severity of the disease and its structural impact on their life.
• Apraxic — Suffering from apraxia or pertaining to apraxia; a person affected by the loss of the ability to execute voluntary coordinated and goal-directed movements, despite intact basic motor and sensory functions. In a structural clinical sense, the term describes clinical manifestations, behaviors, or cerebral lesions associated with the inability to plan and sequence movement schemas.