I. Brain
1.Cortex
(1) Frontal lobe: the pre-central sulcus parallel to the central sulcus and the pre-central gyrus between them support the contralateral random movements.
The lower part of the precentral gyrus is the cranial nerve, the middle part innervates the neck and upper limbs, and the upper part innervates the contralateral trunk and lower limbs. Damage to this area causes: limited epilepsy; damage to the precentral gyrus causes central monoplegia.
(ii) Posterior middle frontal gyrus (lateral visual center): damage causes inability to gaze to the contralateral side.
(iii) Damage to the posterior part of the inferior frontal gyrus of the dominant hemisphere (motor language center) causes motor aphasia; damage to the inferior frontal gyrus of the dominant hemisphere (writing center) causes dysgraphia, which often coexists with motor disorders.
④ Damage to the anterior part of the frontal lobe (origin of the frontal pontocerebellar tract) causes contralateral limb ataxia (absent in paralysis).
⑤ Frontal crest: involved in mental activity. Bilateral lesions cause mental impairment (unresponsiveness).
In summary frontal lobe damage appears as.
1, limited epilepsy (Jackson’s epilepsy).
2. central monoplegia.
3, lateral visual palsy (inability to gaze contralaterally).
4, motor aphasia.
5, ataxia (contralateral).
6, mental disorder.
(2) Parietal lobe
(1) Postcentral gyrus: cortical sensory center that governs the contralateral trunk. Damage causes limited sensory epilepsy (somatosensory seizures) destructive lesions cause contralateral sensory impairment in the corresponding area (cortical type: predominantly fine sensory impairment)
② angular gyrus (reading center): causes alexia in the dominant hemisphere, named aphasia. Posterior angular gyrus injury causes Gutzman’s syndrome (Gerstmom’s syndrome: manifests as loss of writing, loss of counting, inability to recognize fingers, inability to recognize left and right).
(iii) damage to the superior limbic gyrus (motor center): damage causes aphasia; non-dominant hemisphere lesions cause somatotopic disorders (absence of pathosensory perception, inability to recognize self)
(iv) Deep parietal lobe damage causing inferior quadrant blindness.
In summary, parietal lobe damage manifests as.
1, lower quadrant blindness
2. body image disturbance
3, dysarthria
4, loss of reading and naming aphasia
5, contralateral sensory impairment in the corresponding area
6.Somatosensory seizures
(3) Temporal lobe
The posterior gyrus of the superior temporal lobe of the dominant hemisphere (sensory language center): injury causes sensory aphasia. Injury to the medial hippocampal sulcus can cause seizure phantom sniffing followed by epileptic motor seizures, i.e. sulcus gyrus seizures. Deep temporal lobe damage causes superior quadrant blindness.
In summary, temporal lobe damage causes.
1. sensory aphasia
2. sulcus gyrus seizures
3. upper quadrant blindness
(4) Occipital lobe
Irritative lesions cause phantom vision. Destructive lesion causing contralateral hemianopsia (central visual field preserved)
2.Internal capsule
Injury causing: contralateral triple hemianopia (hemiparesis, hemianesthesia, hemianopsia)
3.basal ganglia
Injury causing involuntary movements and altered muscle tone.
2. Mesencephalon
1, thalamus: injury caused by sensory hypersensitivity.
2, hypothalamus.
Injury causing brain-gastric syndrome: vomiting coffee-like substance.
brain – lung syndrome: pulmonary edema.
brain – heart syndrome: arrhythmia.
Central hyperthermia.
Chronic alterations with: uremia.
Triadic syndrome: obesity (impaired lipid metabolism), lethargy, hypogonadism.
iii. cerebellum
Earthworm lesions cause trunk ataxia; hemispheric lesions cause limb ataxia on the side of the lesion, decreased muscle tone, and inability to perform alternating movements.
IV. Brainstem
Crossed palsy
Several common brainstem lesion syndromes
1. Cerebral peduncle syndrome (Weber’s syndrome).
Manifestation: crossed palsy of the motoneurotic nerve (diseased side), contralateral hemiparesis and hemianesthesia.
It is seen in: cerebrovascular disease, inflammation, tumor, brain herniation on one side.
2. Lateral cerebral bridge syndrome (Millard-Gobler’s syndrome).
It is manifested as: peripheral facial palsy, adductor nerve palsy, and central hemiparesis on the opposite side of the disease.
3. Medial pontine syndrome (Foville’s syndrome).
The manifestations are: lateral visual palsy, contralateral hemiparesis.
4.Dorsolateral medullary syndrome (Wallenberg’s syndrome).
Inferior vestibular nucleus: vertigo, nystagmus.
Trigeminal spinal tract nucleus: crossed sensory disorder.
Suspected nucleus: swallowing paralysis, hoarseness.
Windom: ataxia of the diseased limb.
Sympathetic descending fibers: Horner’s syndrome.