Block 5 Neuro Reglodi Case Reviews W Expl

It is a very obvious case, but a rare complication of this type of cancer.

Retinoblastoma, most characteristically appearing at this age, can be suspected when
the tumor reflects light in a strange opalescent way, when light is shed onto the eye
(like when taking a picture with flash) and there is a clear difference between the two
eyes.

Cisplatin is one of the most well-known drug to cause ototoxicity, killing the hair
cells. although the other causes listed could also occur, the induced ototoxicity is the
far most common complication of this treatment.

Because blue cone pigment is coded on another chromosome (not X), it is equally
common in men and women, but altogether it is very rare (duplicate encoding). Red
green pigments are encoded on the X chromosome, so it is much more common in
men.

bitemporal hemianopia is one of the most common first symptoms in pituitary tumors
(he could not see people approaching from the side). Adults usually notice if there is a
visual field loss, it may be hidden for longer times in children. A tumor anywhere in
the brain can present itself by triggering a seizure, in which case it is obligatory to
perform brain imaging. The weight loss can be explained by compression of the
hypothalamus or interfering with pituitary hormones (no information in this case).

Craniopharyngeoma is a tumor of the pituitary, most common onset is childhoodearly
adulthood. In young patients, visual field deficit can be hidden for a long time.
In children, headache can be very characteristic, much more than in adults, but still,
tumors can reach an enormous size before they cause any symptoms.

Multiple sclerosis is a demyelination disease, can start with a wide variety of
symptoms. It mainly affects first long fiber tracts, like the dorsal column of the spinal
cord (leading to gait instability), optic nerve (visual blurriness with pain –optic
neuritis), optic tract and optic radiation with different symptoms depending on the
exact location. The age of the patient in this case is also very typical: it is most
common in young women. The interval between the two attacks is also characteristic,
usually quite a long time passes between two attacks. Many times, just like in this
case, the first attack is not even recognized, patients often remember only at the
second time, that they already experienced something similar in the past.

already in childhood. Later he continued to overproduce GH, so he developed
acromegaly (looking like Shrek). Later all organs can enlarge, so he had cardiac
problems, liver and spleen enlargement, and other symptoms related to increased GH
production (diabetes). For an unknown reason (possible relation to his childhood head
trauma and infection) the tumor is growing downwards, toward the sphenoid sinus, and
then towards the nasal cavity blocking his nasal breathing. The lack of chiasmal
compression (which is usually associated with pituitary tumors) explains why he did not
have visual field deficit.

One-and-a-half syndrome is a neurological disorder characterized by a combination of horizontal gaze palsy in one direction and internuclear ophthalmoplegia in the other direction. This means that the person is unable to move their eyes horizontally in one direction, and has impaired adduction and nystagmus in the other direction. This syndrome is caused by a lesion in the brainstem, specifically in the area where the abducens and medial longitudinal fasciculus (MLF) pathways cross.

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The tumor was above the calcarine sulcus, where the lower visual field is presented,
so the patient has lower contralateral quadrantanopia.

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A pineal tumor would typically compress the cerebral aqueduct and the midbrain
center for vertical gaze (Parinaud syndrome). In this case, the boy did not have the
expected vertical gaze palsy in spite of the huge size of the tumor. But he did have
increased intracranial pressure, severe hydrocephalus, which led to the edematous
papilla and vomiting.

Marfan syndrome patients have a lot of complications, including ocular ones. One can
be retinal detachment, which, in this case is obvious based on the symptoms (painless
blurry vision, occasional lightning sensation).

Although still not used everywhere, tractography is a very useful tool in the surgeon’s
hand to see the exact borders of the future surgery. Especially useful when very impartant
brain areas are involved in/around the tumor (like pyramidal tract, visual pathway).
Temporal lobe epilepsy often leads to temporal lobe sclerosis, which is often resistant to
antiepileptic treatments. So surgery can be necessary. Questioning patients, one of the
most undesired side effects is visual field deficits, which can prevent them from obtaining
driver’s licence, affecting their quality of life in great deal. Therefore, it is necessary to
remove as small area as possible and to avoid visual field deficit due to surgery. The
Meyer’s loop loops around exactly the temporal lobe, and many people forget that
temporal lobe processes can also lead to visual field deficits (most people remember only
the occipital lobe in relation to the visual pathway).

Periventricular leukomalacia is a white matter lesion, characteristic in premature
babies with complications. Often it affects the optic radiation around the occipital
horn of the lateral ventricle, thus, resulting in inferior quadrantanopia.

The lack of abduction of the left eye indicates left abducent nerve palsy. The lack
of pupillary constriction can be due to different lesions, and there was no
information given whether the constriction is preserved upon convergence (which
is necessary for the diagnosis of Argyll Robertson pupil). However, given the
patient`s history (AIDS with various other accompanying infections), this can be
assumed. AIDS patients often have neuro-ophthalmological complications,
including cranial nerve palsy, pupil disorders and optic neuritis. Argyll Robertson
pupil was classically described in syphilis, which is again more common,
especially in HIV-infected patients.

Although very little information is given, but the hypopigmented retina and the lack
of focusing are signs of albinism. Most commonly, albino babies have blue eyes and
very white skin (even white hair), which might not be suspicious at first, given the
age of the baby (2 months old), especially if parents are also very white with blond
hair (common in northern europe for example). The lack of ability to focus can result
in continuous searching movements of the eyes, later nystagmus.

This is a case of isolated trochlear nerve palsy, due to a contusion at the trochlear
nerve exit zone, at the midbrain tegmentum (arrow). Trochlear nerve is the only
nerve exiting on the dorsal side, has a long intracranial course, is very thin, so it is
vulnerable in traumatic injuries. This patient had complete recovery after 1 month

In darkness, photoreceptors are not receiving any light stimulus. This causes sodium channels in the photoreceptor cell membrane to close, preventing the influx of sodium ions. As a result, cGMP levels remain high because there is no activation of phosphodiesterase, which is responsible for breaking down cGMP. This high level of cGMP allows for the continuous opening of cGMP-gated ion channels, maintaining the photoreceptor in a depolarized state. Therefore, the correct statement is that cGMP levels are high in photoreceptors in darkness.

CN IV refers to the fourth cranial nerve, also known as the trochlear nerve. This nerve is responsible for controlling the superior oblique muscle of the eye, which is responsible for downward and inward eye movement. CN IV is unique among the cranial nerves because it is the only one that exits from the dorsal side of the brainstem. Dysfunction of CN IV can lead to weakness or paralysis of the superior oblique muscle, resulting in difficulty with downward and inward eye movement, double vision, and tilting of the head to compensate.

This is a typical case, especially if one cleans his ears by pushing the sebum inwards
with the ear cleaning tips. Webers test in this case would cause better hearing on the
left side (affected), while in Rinne test he would not hear the fork when placed in
front of his ear (conductive hearing loss). Middle ear infection is also possible, but
this also leads to conductive hearing loss, not sensorineural. Epleys maneuver is
applied in vertigo, has nothing to do with hearing.

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On ganglion cells increase their firing rate when their on bipolar cells are depolarized. This statement is true for visual transmission. Ganglion cells are the output cells of the retina and they respond to the activity of bipolar cells. When the on bipolar cells are depolarized, it indicates the presence of light in the receptive field, and this leads to an increase in firing rate of the on ganglion cells.

When you enter from sunlight into a dark room, the retinal pigment in your eyes is bleached due to the sudden change in light intensity. This bleaching process takes time to recover, meaning that your eyes need some time to adjust and regain their sensitivity to light. This explains why it takes a few moments for your vision to fully adapt to the darkness after coming from a bright environment.