Apraxias: A group of cognitive disorders characterized by the inability to perform previously learned skills that cannot be attributed to deficits of motor or sensory function. The two major subtypes of this condition are ideomotor (see APRAXIA, IDEOMOTOR) and ideational apraxia, which refers to loss of the ability to mentally formulate the processes involved with performing an action. For example, dressing apraxia may result from an inability to mentally formulate the act of placing clothes on the body. Apraxias are generally associated with lesions of the dominant PARIETAL LOBE and supramarginal gyrus. (From Adams et al., Principles of Neurology, 6th ed, pp56-7)Apraxia, Ideomotor: A form of apraxia characterized by an acquired inability to carry out a complex motor activity despite the ability to mentally formulate the action. This condition has been attributed to a disruption of connections between the dominant parietal cortex and supplementary and premotor cortical regions in both hemispheres. (From Adams et al., Principles of Neurology, 6th ed, p57)Gait Apraxia: Impaired ambulation not attributed to sensory impairment or motor weakness. FRONTAL LOBE disorders; BASAL GANGLIA DISEASES (e.g., PARKINSONIAN DISORDERS); DEMENTIA, MULTI-INFARCT; ALZHEIMER DISEASE; and other conditions may be associated with gait apraxia.Speech Disorders: Acquired or developmental conditions marked by an impaired ability to comprehend or generate spoken forms of language.Aphasia: A cognitive disorder marked by an impaired ability to comprehend or express language in its written or spoken form. This condition is caused by diseases which affect the language areas of the dominant hemisphere. Clinical features are used to classify the various subtypes of this condition. General categories include receptive, expressive, and mixed forms of aphasia.Ocular Motility Disorders: Disorders that feature impairment of eye movements as a primary manifestation of disease. These conditions may be divided into infranuclear, nuclear, and supranuclear disorders. Diseases of the eye muscles or oculomotor cranial nerves (III, IV, and VI) are considered infranuclear. Nuclear disorders are caused by disease of the oculomotor, trochlear, or abducens nuclei in the BRAIN STEM. Supranuclear disorders are produced by dysfunction of higher order sensory and motor systems that control eye movements, including neural networks in the CEREBRAL CORTEX; BASAL GANGLIA; CEREBELLUM; and BRAIN STEM. Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. Opsoclonus refers to rapid, conjugate oscillations of the eyes in multiple directions, which may occur as a parainfectious or paraneoplastic condition (e.g., OPSOCLONUS-MYOCLONUS SYNDROME). (Adams et al., Principles of Neurology, 6th ed, p240)Agraphia: Loss or impairment of the ability to write (letters, syllables, words, or phrases) due to an injury to a specific cerebral area or occasionally due to emotional factors. This condition rarely occurs in isolation, and often accompanies APHASIA. (From Adams et al., Principles of Neurology, 6th ed, p485; APA, Thesaurus of Psychological Index Terms, 1994)Gestures: Movement of a part of the body for the purpose of communication.Thalamic Diseases: Disorders of the centrally located thalamus, which integrates a wide range of cortical and subcortical information. Manifestations include sensory loss, MOVEMENT DISORDERS; ATAXIA, pain syndromes, visual disorders, a variety of neuropsychological conditions, and COMA. Relatively common etiologies include CEREBROVASCULAR DISORDERS; CRANIOCEREBRAL TRAUMA; BRAIN NEOPLASMS; BRAIN HYPOXIA; INTRACRANIAL HEMORRHAGES; and infectious processes.Ataxia: Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or PERIPHERAL NERVE DISEASES. Motor ataxia may be associated with CEREBELLAR DISEASES; CEREBRAL CORTEX diseases; THALAMIC DISEASES; BASAL GANGLIA DISEASES; injury to the RED NUCLEUS; and other conditions.Hypoalbuminemia: A condition in which albumin level in blood (SERUM ALBUMIN) is below the normal range. Hypoalbuminemia may be due to decreased hepatic albumin synthesis, increased albumin catabolism, altered albumin distribution, or albumin loss through the urine (ALBUMINURIA).Basal Ganglia Diseases: Diseases of the BASAL GANGLIA including the PUTAMEN; GLOBUS PALLIDUS; claustrum; AMYGDALA; and CAUDATE NUCLEUS. DYSKINESIAS (most notably involuntary movements and alterations of the rate of movement) represent the primary clinical manifestations of these disorders. Common etiologies include CEREBROVASCULAR DISORDERS; NEURODEGENERATIVE DISEASES; and CRANIOCEREBRAL TRAUMA.Articulation Disorders: Disorders of the quality of speech characterized by the substitution, omission, distortion, and addition of phonemes.Stereognosis: Perception of shape and form of objects by TOUCH, via tactile stimuli.Gait Ataxia: Impairment of the ability to coordinate the movements required for normal ambulation (WALKING) which may result from impairments of motor function or sensory feedback. This condition may be associated with BRAIN DISEASES (including CEREBELLAR DISEASES and BASAL GANGLIA DISEASES); SPINAL CORD DISEASES; or PERIPHERAL NERVOUS SYSTEM DISEASES.Cerebellar Ataxia: Incoordination of voluntary movements that occur as a manifestation of CEREBELLAR DISEASES. Characteristic features include a tendency for limb movements to overshoot or undershoot a target (dysmetria), a tremor that occurs during attempted movements (intention TREMOR), impaired force and rhythm of diadochokinesis (rapidly alternating movements), and GAIT ATAXIA. (From Adams et al., Principles of Neurology, 6th ed, p90)Speech Production Measurement: Measurement of parameters of the speech product such as vocal tone, loudness, pitch, voice quality, articulation, resonance, phonation, phonetic structure and prosody.Speech Therapy: Treatment for individuals with speech defects and disorders that involves counseling and use of various exercises and aids to help the development of new speech habits.Olivopontocerebellar Atrophies: A group of inherited and sporadic disorders which share progressive ataxia in combination with atrophy of the CEREBELLUM; PONS; and inferior olivary nuclei. Additional clinical features may include MUSCLE RIGIDITY; NYSTAGMUS, PATHOLOGIC; RETINAL DEGENERATION; MUSCLE SPASTICITY; DEMENTIA; URINARY INCONTINENCE; and OPHTHALMOPLEGIA. The familial form has an earlier onset (second decade) and may feature spinal cord atrophy. The sporadic form tends to present in the fifth or sixth decade, and is considered a clinical subtype of MULTIPLE SYSTEM ATROPHY. (From Adams et al., Principles of Neurology, 6th ed, p1085)Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Higher Nervous Activity: A term used in Eastern European research literature on brain and behavior physiology for cortical functions. It refers to the highest level of integrative function of the brain, centered in the CEREBRAL CORTEX, regulating language, thought, and behavior via sensory, motor, and cognitive processes.Agnosia: Loss of the ability to comprehend the meaning or recognize the importance of various forms of stimulation that cannot be attributed to impairment of a primary sensory modality. Tactile agnosia is characterized by an inability to perceive the shape and nature of an object by touch alone, despite unimpaired sensation to light touch, position, and other primary sensory modalities.