Discussion in 'Spot Diagnosis' started by Egyptian Doctor, Nov 12, 2012.
I don't see any abnormality in the tongue per se...so this looks like somebody caught in the act of teasing the Egyptian doctor :hhh:
or ( more likely ) the Egyptian doctor demonstrating CN 12 palsy - in this case Hypoglossal nerve ( 12th CN ) Palsy of right side - at the level of the nucleus or nerve i.e LMN type.
Key - tongue deviates to abnormal side when the patient is asked to stick it out.
Note - UMN lesion involving supranuclear fibers will hav the opposite result i.e tongue deviatiates to opp side.
So with just the pic it's hard to say whether it's upper or lower, but we can say that that 12th cn is involved.
Note : Although, all intrinsic and extrinsic muscles of the tongue are supplied by the hypoglossal nerve (CN XII), except for one of the extrinsic muscles, palatoglossus, which is innervated by CN X of the pharyngeal plexus, this test specifically tests the genioglossus muscle which is responsible for protruding the tongue.
12th CN palsy on the left side (LMN type) will look like this
Lesion n.XII, n.VII
Cn 7 is possible, but can't say from this image - becos the asymmetry that u see may be becos the person is trying to keep his tongue in the center and thus straining one side of his face.
Right Hypoglossal palsy
right hypoglossal nerve palsy
A classic case in relation to our spot diagnosis
[FONT="]A patient displays a deviation of the tongue to the left and a hemiparesis on the right side. The lesion is located in which of the following regions?
[FONT="]A. Right hypoglossal nucleus[/FONT]
[FONT="]B. Left hypoglossal nucleus[/FONT]
[FONT="]C. Right inferior frontal lobe[/FONT]
[FONT="]D. Right ventromedial medulla[/FONT]
[FONT="]E. Left ventromedial medulla
[FONT="]EXPLANATION: A lesion of the left ventromedial medulla would produce a disorder referred to as "alternating hypoglossal hemiplegia" in which there is damage to the hypoglossal nerve as it is about to exit the brainstem and to the pyramidal tract. Damage to the hypoglossal nerve causes a deviation of the tongue to the side of the lesion when it is protruded and a contralateral UMN paralysis of the limbs because these descending corticospinal fibers cross at the medulla-spinal cord border. The other choices do not include structures that were affected in this case. The choice involving the right ventromedial medulla is incorrect because the tongue deviated to the left, not the right side and the paralysis was on the right side of the body, not the left.[/FONT]
[FONT="]The answer is E. [/FONT]
Right Hypoglossal nerve palsy
it s a paralysis of the 12th craniac nerve (hypoglossal ) . Because of the direction of the tongue ,i think its the right 12h nerve that is palsy .
R.Hypoglossal Nerve Palsy (Cr.N XII )
UMN lesion involving the tongue
[FONT="]A 76-year-old woman who has a 10-year history of high blood pressure and diabetes was reaching for a jar of flour to make an apple pie, when her right side suddenly gave out, and she collapsed. While trying to get up from the floor, she noticed that she was unable to move her right arm or leg. She attempted to cry for help because she was unable to reach the telephone; however, her speech was slurred and rather unintelligible. She lay on the floor and waited for help to arrive. Her son began to worry about his usually prompt mother when she did not arrive with her apple pie. After several attempts to telephone her apartment without getting an answer, he drove there and found her lying on the floor. She attempted to tell him what had happened, but her speech was too slurred to comprehend. Assuming that his mother had had a stroke, the son called an ambulance. A neurology resident was called to see the patient in the emergency room because the physicians there likewise thought that she had a stroke. The resident noted that she followed commands very well, and, although her speech was very slurred, it was logical in organization. The lower two-thirds of her face drooped on the right. Her tongue pointed to the right side when she was asked to protrude it. Her right arm and leg were severely, but equally, weak; her left side had normal strength. She felt a pin and a vibrating tuning fork equally on both sides. Where in the central nervous system (CNS) did her stroke most likely occur?[/FONT]
[FONT="]A. Left precentral gyrus[/FONT]
[FONT="]B. Right precentral gyrus[/FONT]
[FONT="]C. Left basilar pons or left internal capsule[/FONT]
[FONT="]D. Right putamen or globus pallidus[/FONT]
[FONT="]E. Left thalamus[/FONT]
[FONT="]EXPLANATION: A CT scan of the patient's head was done in the emergency room, which showed a new infarct or stroke in the genu and anterior portion of the posterior limb of the left internal capsule. This is the region of the internal capsule through which most of the fibers of the corticospinal and corticobulbar tracts pass in a somatotopically organized fashion before entering the brain stem. Because most of these fibers pass through a very small region, a small infarct can cause deficits in a wide distribution of areas. In this case, the patient had weakness in her face and tongue, causing her slurred speech, in addition to weakness of her arm and leg. Since somatosensory fibers destined for the postcentral gyrus occupy a position in the internal capsule caudal to the corticospinal tract fibers, these fibers were spared and she had no sensory deficits. The only other area in the CNS that can cause a pure motor hemiparesis is the basilar pons, an area through which corticospinal and corticobulbar fibers also run. The vascular supply of this region consists of perforators from the basilar artery, which are small and subject to atherosclerotic disease.
[FONT="]The answer is C.
1) This case is typical of UMN type of lesion in which the tongue is involved. The tongue deviates to the side opposite to that of the lesion as opposed to a LMN lesion in which the tongue deviates to the side of the lesion.
2) Second point as to why this case is imp.
Just imagine a lesion affecting the entire precentral gyrus on one side ( middle cerebral artery region ). Can this patient actually be conscious, following such a massive fire selectively involve the precentral gyrus and shy away from the somatosensory area, just next door ? I guess not. And that limit's the possibility of the stoke to the basement area of the brain, where the wires are closely crowded and a small spark can involve large areas ( selectively ).
Note : I am not trying to compare the basement area of the brain to a building basement where a small spark can actually gut the entire building. [/FONT]):[FONT="]
Mechanism of tongue deviation in Geniogloosus palsy
How tongue deviation in Genioglossus palsy is similar to the bending of a bimetallic strip.
I have tried to compare the mechanism of deviation to that of a bimetallic strip (the principle behind the thermostat ) . The explanation in the image below says it all....so I am not saying anything further.
I have a background in physics from where i get the inspiration to compare aspects of human mechanism and behavior with the physical world and viceversa as well ( since I am a keen observer of human behavior as well (-: )
Answer : Right Hypoglossal palsy
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