The central nervous system consists of the brain and spinal cord. The brain is divided into the forebrain, midbrain, and hindbrain. The forebrain includes the cerebral hemispheres which are divided into lobes that control motor, sensory, auditory, visual, and higher cognitive functions. The basal ganglia help control movement. Lesions in specific areas of the brain can cause deficits like weakness, sensory loss, or language problems depending on the area affected. The spinal cord has segments that innervate parts of the body and carry motor and sensory information between the brain and body.

1. Neurological assessment
Dr. Inas Ahmed Al-Amrani

2. Nervous system
The nervous system is divided into central nervous system (CNS) and peripheral nervous system (PNS).
The Central Nervous System (CNS)
Def.
is the part of the nervous system lying within bony cavities. It includes the brain (within the skull) and the spinal cord (within the spinal
canal of the vertebral column).
Function
receives sensation, integrate them and send the motor orders to the peripheral nervous system then to the muscles or glands.
Peripheral Nervous System (PNS)
Def.
• is classified according to its function or its site of origin from the nervous system into:
• 1. Cranial nerves: emerge from the brain stem except olfactory and optic nerves.
• 2.The spinal nerves: originate from the spinal cord
Function
transmits the sensation to the CNS and carries the motor orders to muscles or glands.

4. Brain
Def.
is enclosed within the cranial cavity of the skull, and surrounded by
three protective membranes (meninges).
Subdivisions
1. Forebrain: this includes:
a. Telencephalon: it is the two symmetric cerebral hemispheres
which include the cerebral cortex (gray matter), subcortical
white and the basal ganglia.
b. Diencephalon: it includes the thalami.
2. Midbrain (mesencephalon).
3. Hindbrain: it includes:
a. Medulla oblongata.
b. Pons.
c. Cerebellum.

5. Cerebrum
Def‘.:-It’s the upper and largest part of the brain.
It’s divided incompletely into two hemispheres; Rt.&Lt. cerebral hemispheres by the median
longitudinal cerebral fissure.
At the floor of this fissure a mass of white matter called the corpus callosum unites the 2 cerebral
hemispheres together
• The Cerebral hemispheres occupies the ant., middle and upper part of the post. Cranial fossa
• Covering meningies
The central nervous system is covered by three coverings called meninges. These from inward to outward are pia matter, arachnoid matter and
dura matter.
1.The pia matter fits on very closely to the brain and dips into all sulci.
2.The arachnoid matter is a very thin and delicate membrane and doesn't enter the sulci of the brain. Pia and arachnoid are separated by a
narrow space named the “subarachnoid space" within which the blood vessels of the brain lie.
3. Dura matter is a tough membrane and separated from skull bones by epidural space and from arachnoid matter by subdural space.

7. Areas of cerebral cortex
• The lobes are separated from each other by sulci (fissures):
The central sulcus separates the frontal from the parietal lobe.
The parieto-occipital sulcus separates the parietal from the occipital
lobe.
The lateral sulcus (sylvian fissure) separates the frontal and parietal
lobes from the temporal lobe.

8. frontal lobe
comprises the following important areas:
• "Area 4": is the primary motor area. This area controls the voluntary
movements of the skeletal muscles on the opposite side of the body.
• "Area 6": is the premotor area. It takes part in the control of
extrapyramidal system and gives some fibers to the pyramidal tract.
• "Area 8": is concerned with eye movements and papillary changes.
• ''Areas 44 and 45'' (Broca's area) is an important area for speech.
• "Area 9,10,11,12": are the frontal association areas and are concerned
with higher mental function.

9. Irritative lesion of the frontal lobe leads to:
1-convulsive seizures on the opposite side of the body (focal convulsions).
2-Attacks of conjugate eye deviation to the opposite side of the lesion.
Destructive lesion of the frontal lobe leads to:
1-Contralateral paralysis, contralateral hypertonia of muscles.
2-Paralysis of conjugate eye movement to the opposite side of lesion.
3-Motor aphasia and Agraphia.
4-Mentality, personality and behavioural changes.
5-Incontinence urine and faeces.

10. parietal lobe
comprises the following important areas:
• "Areas 3,1,2”: are considered the primary sensory areas.
• "Area 5 and 7": are the sensory association areas. They are concerned
with steriognosis and graphoesthesia.
Irritative lesion of the parietal lobe leads to:
1. Contralateral sensory Jaksonian fit.
Destructive lesion of the parietal lobe leads to:
1. Contralateral cortical sensory loss.
2. ALexia, Garone's aphasia (word salad and apraxia.
3. Asteriognosis.

11. temporal lobe
comprises the following important areas:
• "Area 41and 42": these are the primary auditory areas.
• "Area 22": is the auditory association area and is responsible for knowing the meaning of
sounds.
Irritative lesion of the temporal lobe lead to:
- Auditory hallucination.
Destructive lesion of the temporal lobe lead to:
1-Slight hearing impairment.
2-Auditory agnosia.
3-Temporal seizures.
4-Anterograde amnesia.
5- Perceptive aphasia (in ability of the patient to know the meaning of heard sounds.

12. occipital lobe
comprises the following important areas:
• "Area 17": it is the primary cortical visual area.
• "Area 18 and 19": are visual association areas and are responsible for
knowledge the meaning of the pictures or words seen.
Irritative lesion of the occipital lobe lead to:
-Visual hallucination sparks, lines, flashes
Destructive lesion of the occipital lobe lead to:
1-Homonymous hemianopia.
2-Visual agnosia.
3-Paralysis of reflex conjugate eye movement.

13. THE BASAL GANGLIA
• The basal ganglia are
masses of grey matter
situated deeply within the
cerebral hemispheres.
• They are formed of 4
nuclei: caudate, lentiform
(putamen and globus
pallidus), amygdaloid and
claustrum nuclei.
• Caudate and lentiform
nuclei are the main part of
the extrapyramidal system.
• Amygdaloid nucleus is
concerned with smell and
emotion.

14. THE BASAL GANGLIA
Basal ganglia dysfunction: Defects in function of the basal ganglia
(sometimes termed extrapyramidal lesions) produce movement
disorders in the form of:
Akinesia or bradykinesia e.g. parkinson’s disease and parkinonism.
Hyperkinesia or dyskinesia e.g. chorea.
Dystonias and tics

15. DIENCEPHALON
The diencephalons includes: thalamus,
subthalamus, hypothalamus and
epithalamus.
• Thalamus is considered to be the
subcortical station for all types of
sensation (especially pain) except
olfaction.
• Lesions of the thalamus produce thalamic
syndrome which is caused mainly by
vascular aetiology.
• Subthalamus: leis between the midbrain
and the thalamus and it is mainly
connected to the extrapyramidal system.
• Epithalamus: concerned with olfaction.
• Hypothalamus: it leis below the thalamus
and has wide varieties functions, among
these functions are: temperature control,
autonomic nervous system control,
endocrine control, emotional stress
reaction, etc.

16. Brain stem
• THE BRAIN STEM consists of the midbrain (mesencephalon), pons,
and medulla oblongata.
• It contains the nuclei of the cranial nerves (the exceptions are the first
two cranial nerve nuclei),

17. Brain stem
Midbrain: is the short portion of the
brain stem between the pons (below) and
deincephalon (above).
•The midbrain can be divided into three
main parts:
1.The tectum (quadrigeminal plate).
2. The tegmentum, which is a
continuation of the pons tegmentum.
3.The very large crus cerebri, which
contains the corticofugal fibers.
• The midbrain contains two cranial
nerve nuclei, the oculomotor and
trochlear nuclei and two cerebral
peduncles.
•The most prominent nuclear mass in
the midbrain is the substantia nigra,

18. Brain stem
• Pons: it leis between the
medulla (below) and mid
brain (above) and in front
of the cerebellum.
• It includes, transverse
pontine fibers and pontine
nuclei, and the trigeminal,
abducent, facial and
vestibule-cochler nerve
nuclei.

19. Brain stem
• Medulla oblongata: connects the
pons superiorly with the spinal
cord inferiorly.
• The medulla can be divided into
a caudal (closed) portion and a
rostral (open) portion. The
division is based on the absence
or presence of the lower fourth
ventricle.
• It includes: pyramids, olive,
gracile, decussation of pyramids,
cuneate tubercle and cranial
nerve nuclei of the
glossopharyngeal, vagus,
accessory and hypoglossal
nerves.

20. CEREBELLUM
• The cerebellum is located in
the posterior fossa of the skull
behind the pons and upper
medulla and is separated from
the overlying cerebrum by an
extension of the dura matter
named “tentorium cerebelli”
• It is composed of vermis and
two lateral masses “cerebellar
hemispheres”.
• Lesion of cerebellum produce
trunkal ataxia, swaing,
staggering gait, hypotania,
dysmetria, intention tremors
and inability to perform rapid
alternating movements
(Adiadochokinesia).

21. VENTRICLES
There are 4 ventricles in the
brain: the two lateral
ventricles, the third ventricle
and the forth ventricle.
• The lateral ventricle is the
cavity of each cerebral
hemisphere.
• The third ventricle is the
cavity of the diencephalon
(between the two thalami).
• The fourth ventricle is the
cavity of the hind brain
(pons, medulla and
cerebellum).

22. VENTRICLES
• The lateral ventricles are connected
with the third ventricle by the “foramen
of Monro” (interventricular foramen)
and the third ventricle is connected with
the forth ventricle by the “Aqueduct of
sylvius’’ (Aqueduct of the midbrain).
• The fourth ventricle is connected to the
subarachnoid space by the foramena of
magendi and Lushka.
• Obstruction any where within the
ventricular system produces
hydrocephalus and this type of
hydrocephalus is named “internal or
obstructive or non-communicating
hydrocephalus”.

23. CRANIAL NERVES
There are ‘12’ pairs of cranial nerves
• I- Olfactory: modulates smell.
• II- Optic: modulates vision.
• III- Oculomotor, IV- Ttochlear and VI-
Abducent concerned with ocular
movements and papillary reactions.
• V- Trigemenal: sensory to the face and
anterior 2/3 of the scalp and motor to
the muscles of mastication‫ز‬
• VII-Facial nerve: modulates motor to
muscles of expression, frontalis,
orbicularis oculi, buccinator, orbicularis
oris, retractor angularis and stapedius
muscles.
-Secretory: to salivary glands and the
lacrimal gland
-Taste sensation: anterior 2/3 of the
tongue
- Sensory: External auditory meatus.

24. CRANIAL NERVES
• VIII- Vestibullocochlear nerve:
-Vestibular division: modulates
equilibrium.
-Cochlear division: modulates hearing.
• IX- Glossopharyngeal, X- Vagus and
- Accessory (cranial part) supply palatal,
pharyngeal and laryngeal muscles.
- Spinal part of accessory: supplies
sternomasoid and trapezius muscles.
• XII- Hypoglossal supplies extrinsic and
intrinsic muscles of the tongue except
palatoglossus.
• There are 12 cranial nerves classified
according to the type of the fibers they
contain.
1- Purely sensory nerves:1,2 and 8.
2- Purely motor nerves:3,4,6,11,12.
3-Mixed (sensory and motor) nerves:
5,7,9,10.

25. SPINAL CORD
• Spinal cord is the part of the CNS
contained within the spinal canal of
the vertebral column. It is
composed of ‘31’ segments
arranged as follow: ‘8’ cervical,
‘12’ thoracic, ‘5’ lumbar,
‘5’sacral and ‘1’ coccygeal.
• The spinal cord ends at the lower
border of the first lumbar vertebra.
Thus, each segment of the spinal
cord does not correspond to the
same vertebra.
• The spinal cord segment consists of
central gray matter and peripheral
white matter which is classified
into columns (posterior, anterior
and lateral) where tracts ascend or
descend.

26. SPINAL CORD
• The end of the spinal cord has special
characters and contains the following
regions: conus medullaris (sacral
segments number 3,4 and 5) and
epiconus ( lumbar segments 4 and 5
and sacral segments 1 and 2).
• Cauda equine: are the roots that fill the
spinal canal after the end of the spinal
cord.
• Spinal cord disorders lead to weakness
in a upper motor neuron (UMN) pattern
below the lesion, and weakness in a
nerve root pattern at the level of the
lesion. There are may be sensory loss
below the level of the lesion due to
interruption of ascending tracts.

27. SPINAL NERVES
There are '31' pairs of spinal
nerves corresponding to the spinal
segments. These nerves have short
trunks formed by combination of
the dorsal root (sensory) and
ventral root (motor) in the
intervertebral foramen of the
corresponding vertebrae. These
spinal nerves divide immediately
after emerging from the
intervertebral foramen into two
unequal divisions, large medial
division and small lateral division.
Each of these divisions contains
both motor sensory fibers which
supply all skeletal muscles of the
body and convey all modalities of
sensation to the ascending tracts
of spinal cord.

28. investigations
• X-ray
• C.T
• MRI
• EEG
• EMG