Saturday, April 8, 2017
Friday, April 7, 2017
Thursday, April 6, 2017
Alien Hand Syndrome!
Hello everybody!
So today I will be writing a post on the movie Dr.Strangelove, suggested to me by a dear friend!
In the movie..the character called as
Peter Sellers constantly has to restrain his alien hand from giving the Nazi party salute.
The condition the character was suffering is called as Alien Hand Syndrome.
Let's understand what exactly is alien hand syndrome.
In this Syndrome there is complex, goal directed but involuntary activity in one hand; the hand moves as if it had a mind of its own.
It is usually due to interruption of the cortical connections that control smooth bimanual operations.
The hands no longer work as a team.The affected hand begins to function autonomously and loses the ability to cooperate with its fellow.
If the patient tries to eat with the good hand, the alien hand may grasp the good hand and force it away from the mouth.
There are two forms of it:
Callosal form:
In this form there is a lesion in the anterior corpus callosum.
Intermanual conflict is typical and it nearly always affects the left hand.
Frontal form:
In the frontal form, there is a lesion of the medial frontal lobe. The alien hand is uncooperative but not contentious. It may display reflex grasping and other autonomous behavior, but there is little or no intermanual conflict.
Patients may complain of the hand’s behavior, and may criticize it ,
on the other hand (No pun intended here) patients regard the hand’s behavior as amusing.
A sensory alien hand syndrome has also been described following right posterior cerebral distribution stroke. There are typically parietal sensory deficits and hemineglect involving the left side of the body, which resemble anosognosia.
The right arm may then involuntarily attack the left side of the body.
I hope this was informative!
I love watching Movies which integrate medical conditions, do let me know your suggestions too!
Let's Learn Together!
-Medha!
Wednesday, April 5, 2017
Drugs causing Hyperkalemia mnemonic
Lets remember drugs which cause rise in serum potassium levels:
Fisher's Rules.
Hello Everybody!
So today I will be telling you guys about the “Fisher’s rules” that I came across while striving to develop good clinical skills while doing my internship!
So these rules are basically clinical maxims collected from observing C. Miller Fisher, a clinician of legendary diagnostic acumen. Some of these axioms are particularly helpful to bear in mind and are relevant for Clinical Reasoning and useful as diagnostic Principles.
So here we go, while seeing the patient for the first time we better keep the following 6 rules in our mind.
1) In arriving at a clinical diagnosis, think of the five most common findings (historical, physical findings, or laboratory) found in a given disorder.
If at least three of these five are not present in a given patient, the diagnosis is likely to be wrong.
2) Resist the temptation to prematurely place a case or disorder into a diagnostic cubbyhole that fits poorly.
Allowing it to remain unknown stimulates continuing activity and thought.
3) The details of a case are important; their analysis distinguishes the expert from the journeyman.
4) Pay particular attention to the specifics of the patient with a known diagnosis; it will be helpful later when similar phenomena occur in an unknown case.
5) Fully accept what you have heard or read only when you have verified it yourself.
6) Maintain a lively interest in patients as people.
I found these extremely useful while seeing patients in real and so thought of sharing these.
Medicine in practice is more than just Studying the Standard textbooks, It's an Art that we should all strive to Master,so we can help our patients better.
Its a long journey ahead... Let's Learn Together!
-Medha!
Monday, April 3, 2017
Can watching Pokémon cause seizures?
Hello everybody,
So this is an interesting post about Stimulus Sensitive seizures also known as Reflex Seizures.
The major stimuli precipitating these seizures are Sensory in nature but as there is no known "Reflex" to cause such seizures they are better termed as Stimulus Sensitive Seizures!
So in order to study these seizures Japanese children were exposed to Pokémon cartoon that induced seizures, surprisingly out of all the children who had an episode of seizure only 24% had a history of spontaneous seizures. These children had the Photosensitive type of Stimulus Sensitive seizures.
Photosensitive or pattern-induced seizures as experimented in the Japanese kids are, well-recognized and stimulated by bright or flashing lights (TV, video games, discotheques, concert light shows) or by patterns (lines on the road while traveling). These may occur 1 in 4,000 people in age group of 5-25yr but are outgrown in their 30s.
For patients with isolated photosensitive or pattern-induced seizures, avoidance or modification of stimuli is the initial approach in the form of wearing blue or polarized sunglasses, avoiding highcontrast flashing-light video games,
avoiding discotheques, watching TV in a well-lit room at a distance of >8 feet, and covering 1 eye when in a provocative situation.
Well generally it is observed that many patients with epilepsy can identify precipitating or provoking events that predispose them to having a seizure.
Common events include :
stress
lack of sleep
fever
fatigue.
In another group, patients have seizures in response to a very specific, identifiable sensory stimulus or activity.
These stimuli may be :
External :(light, patterns, music, brushing teeth)
Internal :(math, reading, thinking, self-induced).
The manifestation of these seizures can be either:
Generalized
Partial
Nonconvulsive
Absence
Myoclonic.
One common pattern is photomyoclonic seizures characterized by forehead muscle twitching or repetitive eye opening or closing.
So till the next time you play Pokèmon Go or you see Pikachu in action do remember about Stimulus Sensitive Seizures! ;)
Hope this was informative!
-Medha!
Sudden Unexpected Death in Epilepsy - SUDEP.
Hello everybody,
Let's today learn about Sudden Unexpected Death in Epilepsy.
It is the most common epilepsy related mortality in patients with chronic epilepsy.
Incidence: ranges from 1-5 per 1000 patients.
Etiology: unknown, but some of the risk factors include :
1)Polypharmacology,
2) Poorly controlled generalized tonic clonic seizures
3) Male gender,
4) Age younger than 16 yr,
5) Long duration of epilepsy, and frequent seizures.
Potential mechanisms include :
1) Respiratory arrest or dysfunction,
2) Drug-induced cardiac toxicity,
3) CNS dysfunction (hypoventilation, arrhythmia, suppression of brain electrical activity)
4) Pulmonary edema.
Patients are usually found dead in their bed in prone position with evidence suggestive of a recent seizure.
Some of the Preventive measures include:
1)Reduction of tonic–clonic seizures: optimum treatment, good drug compliance, lifestyle advice (e.g. avoiding sleep deprivation)
2)Treatment changes: change drugs in a gradual staged manner; when switching, introduce the new drug before withdrawing the old one.
3)Supervision at night for patients at high risk.
4) Choice of drugs: caution with antiepileptic drugs with potential cardiorespiratory adverse effects.
5) Action on ictal warning signs:
tonic–clonic seizures that are prolonged, associated with marked cyanosis, severe bradycardia or apnea, complex partial seizures with marked atonia (drop attacks);
Lastly counseling on the risks, lifestyle modifications. The treatment decisions are the patient’s prerogative, the physician’s role is to provide a risk-vs-benefit analysis.
Hope it was informative.
Let's learn together!
-Medha!
Micro-organism series -Salmonella
Introduction: Salmonella belongs to the type of parasites which infects the intestine of vertebrates and causes infection.It causes following infections (Mnemonic - "GAS".)
G - Gastro-enteritis
A - Abdominal fever or enteric fever
S - Septicemia
The species Salmonella-typhi was first observed by Eberth in mesenteric lymph nodes and spleen and was first isolated by Gaffky and hence is also known as Eberth -Gaffky or Eberthella -typhi .
S.cholerae - suis the first organism to be isolated from animals and human beings.
Salmonella is divided into two groups :-
1)Typhoidal Salmonella :Causes typhoid fever eg S.typhi and S.paratyphi A,B,C
Man is the only reservoir
2)Non-typhoidal : They have many animal reservoir .To remember species name, here is a mnemonic
"Hodor held typhimurium to enter into port "
Hodor -S.hadar
Held- S.heidelbrurg
typhimurium-S.typhimurium (to)
Enter-S.enteridies
Port-S.new port
Morphology:
Aerobes and facultative anaerobes
Gram negative bacilli
It is motile with peri-trichate flagella except S.Gallinarum and S.Pullorum .
Non-capsulated and non-sporing .
Cultural characteristics:
Can grow on simple media over pH-6-8
Temperature:15-41℃
Colonies are circular ,low-convex and smooth .
1)Mac-Conkey's agar(Differential media) :Non-lactose fermenting colonies
2)Deoxycholate citrate and XLD(Selective media): Black head due to hydrogen sulphide production
(Deoxycholate citrate agar and Mac-Conkey's agar are selective as well as differential media)
3)Wilson & Blair bismuth sulphite medium(Indicator medium):Black colony with metallic sheen due to production of hydrogen sulphide.Only S.typhi produces black colony .Paratyphi A produces green colony as it does not form hydrogen sulphide.
4)Selenite F broth and tetrathionate broth is the enrichment media used for both shigella and salmonella
Biochemical tests:-
1)It ferments Glucose ,mannitol and maltose producing acid and gas
2)IMViC : - + - +
3)Most salmonella produces hydrogen sulphide in Triple sugar iron(TSI) test except S.parathyphi A and S.Cholerae suis .
4)S.Gallinarum and Pullorum cannot be differentiated but can be identified by biochemical reactions .S Gallinarum ferments dulcitol unlike Pullorum .
Resistance:
Killed in 1 hour at 55℃ or in 15 mins at 60℃
Boiling ,chlorination and pasteurisation destroys bacteria .
Killed in 5 minutes by using mercuric cholride / 5% Phenol .
Survives for weeks in polluted air & water
Survives for months in ice
Survives for years if prevented from drying .
Antigenic structure:
There are 3 antigens present in salmonella
1)Flagellar antigen H:
- Heat labile
- Present on flagella
- Highly immunogenic and hence form high titre of antibodies
- Destroyed by alcohol or boiling
- When mixed with antisera , agglutination is rapid producing large ,loose and fluffy clumps.
- H persists longer than O agglutinins
2)Somatic antigen "O"
- Integral part of cell wall
- Identical to endotoxin
- Less immunogenic
3)Vi antigen :
- Heat labile polysaccharide and it prevents the agglutination of O antigen
- Act as virulence factor by preventing phagocytosis.
- Persistance of Vi antigen indicates carrier state
Pathogenesis:
Transmission:Normally food contaminated by the faeces of the animal or humans who carries salmonella
Mode of transmission:Ingestion
Incubation period :7-14 days for enteric fever
Pathogenicity :
Salmonella infection usually causes
Gastroenteritis
Enteric fever
Septicemia
Clinical symptoms:
Clinical course may vary from mild to undifferentiated pyrexia (Also called as ambulant typhoid)
- Onset :Gradual with headache ,malaise ,anorexia ,a coated tongue and constipation or diarrhea.
- Step ladder pyrexia.
- Palpable spleen
- Rose spot appearence on chest during 3rd or 4th week .
- Complications occurs in 3rd and 4th week causing intestinal perforation and GI hemorrhage (most common )
- Pea soup stools in 3rd week of typhoid fever
- Some degree of bronchitis or bronchopulmonary spasm is always seen
- Osteomyelitis is rarely seen mainly in patients affected with sickle cell anemia .
Laboratory diagnosis :
Specimen :
Blood is collected for culture ,as in urine or stool .
Serum for Widal test .
(A very famous mnemonic for collection of sample depending upon time duration is
"BASU")
B - Blood culture in 1st week of infection
A - Antibody (Widal in 2nd week of infection)
S - Stool culture in 3rd week of infection
U - Urine culture for 4th week of infection.
Best diagnosis is made by blood culture at any stage .
Detection of Vi antigen indicates carrier state.
If antibiotics is started we must use faeces or bone marrow for laboratory diagnosis .Since antibiotics kills bacteria from the circulation and if not started then we can use blood culture .
Treatment:
Ceftriaxone is the DOC
Ciprofloxacin is the DOC for susceptible organism .
Other drugs used are azithromycin ,amoxicillin,chloramphenicol
Carrier :Ampicillin or amoxicillin given for six weeks
Salmonellosis:
Non Thyphoidal salmonellosis(NTS) is -commonest type of salmonellosis
Factor causing NTS
Immunosuppressive agents like increase in age ,Disease such as HIV etc.
Clinical manifestation:
Gastroenteritis most common .Diagnosis is done by gastroenteritis .
Localized infection like abscess ,meningitis , Osteomyelitis.
Treatment:
DOC either ceftriaxone or Ciprofloxacin .
That's it :P
Stay awesome and cool:)
~Khushboo and Ojas
Sunday, April 2, 2017
Testosterone and Dihydrotestosterone
Hello awesomites today I am going to share my notes on functions of Testosterone and Dihydrotestosterone .
Testosterone is regarded as the circulating prohormone.In most of the target cells , testosterone is reduced to Dihydrotestosterone (DHT) which is more potent than the testosterone.
Testosterone function:
Remember: LISE
-LH inhibition .
-Internal genitals development .
-Spermatogenesis
-Erythropoiesis.
Dihydrotestosterone function
Remember :"PG says hair growth,behaviour changes and development of external genitals is due to DHT "
(Half of the things you all must have got through it!)
PG-Prostrate growth .
Behaviour changes ,Sexual growth .
Hair growth .
External genital development.
Function which is done by both hormones?
-Increase in muscle mass and strength of bones
Stay cool and awesome:)
~Ojas
Watermelon stomach- GAVE!
Friday, March 31, 2017
Ion-exchange resins and Laxatives
In my last post on Hyperkalemia, I asked this question that why do we give laxatives with ion-exchange resins, eg. Sodium polystyrene sulfonate.
The reason is that if there is constipation due to Hyperkalemia or any other condition we are treating, besides these ion-exchange resins can themselves cause constipation; these resins will be stuck in the colon and the ion to which it is bound to will be reabsorbed into the circulation hence foiling the whole agenda.
-VM
Difference between polysaccharide vaccines and conjugated vaccines
The new generation conjugate vaccines contain carrier proteins that are chemically attached to the polysaccharide antigens. Attaching relatively non-immunogenic polysaccharides to the highly immunogenic carrier proteins means that by activating a T-cell response, conjugate vaccines induce both high-affinity antibodies against the polysaccharide, and immune memory.
So in conclusion:
Polysaccharide vaccine - T cell independent B cell response
Conjugate vaccine - Carrier proteins - T cell dependent B cell response
Mnemonic:
CT (Like a CT scan?)
ConjugaTe has a T cell response
Trastuzumab notes + mnemonic
ARDS pathophysiology Q&A
Compliance
Pulmonary artery pressure
Pulmonary capillary wedge pressure
A-a gradient (Alveolar-arterial gradient)
PaO2 / FiO2
Answers given below!
