Note (first physiology lecture sheet Page 5)
The patient doesn’t see the spoon by the dominant half that’s why he says
“nothing”. However, he sees it with the right hemispheres but it cannot be
verbalized what it sees.
Three types of epilepsy are going to be discussed in this lecture :
1) Grand mal epilepsy :
 it involves ALL THE BRAIN (not only the cortex) (high frequency, high
amplitude in all electrodes)
 -it is preceded by an aura … so if the patient is standing or sitting he
would lie on the ground preparing himself for the fit.
 epileptic patients are not allowed to drive cars
 the fit has two phases :
a) tonic phase: all body muscles go to spasm (including respiratory
muscles so the patient will suffer from cyanosis), lasts about a
minute
b) clonic – tonic phase : jerky movements in arms and face,
urination and defecation may occur as well due to contraction of
abdominal wall muscles (increased intra-abdominal pressure).
Clenching of teeth, biting of tongue and froth from the mouth
can be seen. Respiration returns in this phase.
c) Stupor
d) Sleeps and wakes up with a headache
In status epilepticus (state of persistent seizures), patients may die due to
cyanosis.
You can’t help this patient by any means … just let him relax after the fit and
advice to visit a neurologist to adjust his medications
 the fit stops after a while due to synaptic fatigue (slef-limiting)
notice that the scale for grand mal epilepsy in the diagram is the largest (1cm 
100 microvolts compared to 50 in the other two) so it involves the highest
voltage changes.
The recordings we have in our slides are for epileptic patients DURING the
epileptic fit. At other times patients have normal EEG.
2) Petit mal epilepsy
 Occurs in children
 Periods of Absence, child playing suddenly falls and his eyes roll.
 3-30 seconds during which the child doesn’t hear anything.
 Might be annoying if the child suffers this for like 16 times in 50
minutes lectures as he would not understand anything.
 Easily controlled by drugs
 Diagnosed by EEG (pathognomonic “spike and dome”, with about 3Hz
frequency), even if it appears in a SINGLE electrode
 Recovery :
disappears at adulthood
develops to grand mal epilepsy with absence
disappears in 30s of age
3) Focal epilepsy (this is what is called in Arabic as ‫)شحنات زائدة‬
 Involves a certain area
 The patient needs an MRI to check for lesions, MS, tumors … etc
 Young individual with frequent attacks of syncope (frequent : up to
weeks)
Differential diagnosis of syncope:
1) Vasovagal responses in a senstitive pt. (patients cannot withstand
heat …. Etc)
2) Arrhythmias
3) Focal epilepsy
 The patient might immediately faint and injure his head. (should be
medicated)
 e.g. temporal lobe epilepsy causes aggressiveness (patients can commit
crimes) due to involvement of the limbic system and hallucinations.
 EEG: all small peaks (in the range of 50 microvolts with few abnormal
spikes)
Illusion (misconception) : when u focus on one side u find the other side not equal.
Hallucination: perception without the presence of external stimuli. E.x: watching or
hearing things that r not exist.
Delusion: A believe in a thought that is not present. E.x: writing some words and
numbers and considering it as the most important theory ever !!
# The eye : beside watching and recognizing things, it is a very important part of
memory which is a part of the intellectual capability of the person . it consists of :
1-sclera: protective layer modified to form the cornea anteriorly. Cornea gets its
nutrients not from the blood vessels - bcz their existence hampers the vision - but from
tears, neurotropins from the fibers and from the aqueous in the anterior champer. It is
responsible of 80 % of refractory ?? Which is more important than the lens?
2- choroid: vascular and pigmented with melanin - preventing the extra reflex and
clarifying the image – so the albinism people can't see very well. This layer forms the
ciliary body anteriorly and the iris.
3- Retina: it has no anterior modification.
# Some people may complain of something moving from up down or right to left while
seeing the sky for e.x. It is called flutters and it is the remnant of cellular debri and
appears during moving the head. It is not dangerous.
# Receptors of vision are formed of rods and cons which are found behind the ganglion
and bipolar cells. The electrical signal comes back to ganglion cells then to the optic
nerve in a reverse way to the entry of light.
# Unilateral blue eye is usually a cause of aggression and domestic violence and not by
falling bcz the eye is protected by the orbit.
# This patient mustn't leave the hospital without full examination of the eye by
ophthalmoscopy bcz she might come back in two days complaining of losing the vision
of that eye – unilateral ecomosis - which is difficult to treat. This is because of retinal
detachment from choroid as a result of accumulation of fluid. So the receptors which r
impeded in the choroid lose their source of nutrition which is a big deal!!
-Bilateral blue eyes trauma (also called panda eyes or raccoon eyes)
happens due to fracture to the skull base in car accidents. The periorbital
area appears blue due to ecchymosis as the blood accumulates under the
skin of the eyes.
-In case of fracture of the skull base YOU AS A DOCTOR should wait 24
hours after the injury as the linear fracture does not appear until 24 hour in
X-Ray because the calcium needs 2-3 day to start accumulation in the
fracture area then appear in the X-ray. So you need another X-ray after 2-3
day then you can judge whether there is fracture or not because there will
be legal problems.
-Base fractured can be diagnosed by 1- otorrhea 2- rhinorrhea 3- periorbital
ecchymosed in both eyes 4- Battle's sign.
-Cortisone is very helpful in this case to reduce the edema that can affect
some cranial nerves.
-The fracture in bone when it happens will tear the meninges that attach to
the fracture bone and the blood from meninges will therefore leak out
from the fracture tear to soft tissue like the skin of periorbital area.
-The doctor here should tell the patient not to cough , strain( in case of
constipation) or become angry as the increased intracranial or
intrabdominal pressure in those condition will worsen the shear in
meninges and then we need to open the skull through a hole and take the
blood out with intensive care to the patient (intensive care should be
provided even in uncomplicated cases).
Vision pathway abnormalities
-Perimetery eye test is a test to examine the eye field. The field of each eye
is wide that the right eye field extends from the far right to reach the left
area and this is true for the left eye so there is overlap between the fields
of both eyes.
-A common mistake is when we ask about an injury to the right optic nerve
and we see that there is lose of the right field. But the true is that the loose
will be in a partial part of the right field as the field of the left eye extends
to right.” Ye3nee blindness in the right eye but not in the right field.”
-The R and L optic nerve will form the optic chiasm then they will form R
and L optic tract that will reach the dorsolateral geniculate nucleus in the
dorsal part thalamus.
-Some fibers of the optic tract will reach the ventrolateral geniculate
nucleus in thalamus. This nucleus is responsible about the “EYE
LANGUAGE” when you try to express your emotional feeling through your
eyes.
-These fibers will join other parts of the body (like facial muscles) which will
collectively perform your emotion or mood (loving
, hating,
,
happy ^_^ , ungry ( -_-' ) etc…)
-Some fibers from optic chiasm will go to suprachiasmatic nucleus and it
function in circadian(diurnal )rhythm.
- Some fibers from optic tract will go to pretectal nucleus and it functions in
light reflex ,other fibers go to superior coliculus and functions in conjugate
eye movement
-The retina is two parts Superior and inferior .Superior part of retina is
represented medially in lateral geniculate nucleus and superiorly in the
calcarian fissure. And inferior part of retina is represented laterally in
lateral geniculate nucleus and inferiorly in the calcarian fissure.
-the macular are situated posterior in the optic chasm and posterior in the
occipital lobe. The macula includes the fovea that contains the largest
concentration of cone cells in the eye and is responsible for central, high
resolution vision.
Lesions in the optic pathway
-A lesion in the right optic nerve >>>>>> Right eye blindness and partial
right field loss.
- A lesion in optic chiasma >>>>>>> Bitemporal heteronymous hemianopia
.It is late sign of pituitary gland tumor that involved the optic chiasma
extensively and the tumor is inoperable. Pituitary tumors or silla turcica
tumors initially involve the posterior part of the chiasma (macular fibers)
then the inferior fibers (Upper temporal quadrant). So the patient will
complain at first from Scotoma (blind spot in both eyes due to macular
fibers damage bilaterally) which is not felt by the patient but can be
diagnosed by perimetery test where the eye field is having a hole in the
fovea.
-A lesion in optic tract before the geniculate nucleus >>>>> contralateral
homonymous hemianopia.
-A lesion in optic tract after geneculate nucleus in the lower optic radiation
that pass through the temporal lobe(called meyer’s lobe) resulting from
temporal tumor >>>>contralteral upper quadrantinopia (in those patient
there will be pie in the sky in the perimetery test )
-in occipital tumors in children the macula will be spared because the
posterior part of occipital lobe is affected late in the course. So in right
occipital tumor there will be contralateral quadrantinopia( upper or lower
)then it will be contralateral hemianopia with sparing the macula in both
cases but in the end the macula will be affected.
-The peremeter test is useful to diagnose stroke ,tumors, MS ,degenerative
diseases.
Done by
zaid wakeleh , ma2moun and mokhtar