Basal Ganglia Circuit

Hello everyone!  Confusing loop has now simplified look! 👀 

First of all, Basal ganglia receives cortical input, provides negative feedback to cortex to modulate movement.

3 things must be remembered. 

• SNc (Substantia nigra) input to the striatum via the nigrostriatal dopaminergic pathway releases GABA.
• Dopamine binds to D1 , stimulating the excitatory pathway, and to D2 , inhibiting the inhibitory pathway. 
• Pathways from Thalamus to Motor cortex & from Motor cortex to Basal ganglia - “Stimulatory” 

That’s why this circuit is important in voluntary movements and adjusting posture. 

Here is my attempt to simplify this circuit through a drawing. By understanding that you’ll never forget it! 

• I-N-hibitory pathway goes through Gp-I & N-ucleus(Subthalamic)!
• If BG output = +, then increased motor activity
• If BG output = -, then decreased motor activity 

In PARKINSON’S DISEASE, SNc degenerates = lose dopaminergic input to BG

Less stimulation of direct pathway (⬇️gas) and less Inhibition of Indirect pathway (⬆️ brake) = overall indirect wins =less motor activity. This explains bradykinesia and rigidity of PD but not tremor. 

STN and GPi are targets of Deep Brain Stimulation in PD. 

Deep brain Stimulation INHIBITS activity in these structures—inhibiting either would lead to decreased inhibitory output of BG = increased motor activity-> improve PD symptoms. 

Lesion of STN -HEMIBALLISMUS= uncontrolled erratic large amplitude movements on one side.  Why INCREASED movement with STN lesion? 

By decreasing STN excitation of GPi we essentially ‘remove’ indirect pathway from equation, and direct pathway becomes unchecked -> ⬆️ movement      

Thank you! 🩺

Ehler-Danlos Syndrome (EDS) - High yield only

Hi! So let's learn EDS together. I've tabled a list of high-yield points of all the types of EDS. It requires little bit of revision but once you get a pictorial familiarity you should be able to recall them all. 

Have fun!

So, how to remember?

Step 1. Divide the table into 2 halves. Sl no. 1,2,3 have in common a lot of features:

• They are all Autosomal Dominant. 
• They have common Clinical features - skin HYPERelasticity, joint HYPERmobility and HYPER (easy) bruising. 
• Go serially, Classical has the first 2, Type I and II and HYPERmobile is III and lastly Vascular is type IV 
• Vascular type has additionally - arterial & uterine rupture.

Step 2. Now the second section Sl no. 4,5,6

• EDS types with enzyme defects are Autosomal Recessive. So, 4 and 6 are AR. 
• Kyphoscoliotic EDS is Type VI (K rearranged is a V and I)
• For the last 2, mnemonic is ABCD😛 Arthrochalasia VII a, b and VII c is Dermatosparaxis.
• KyphoSCOLIOTIC EDS - defective lysyl hydroxylase (=> abnormal cross linking of collagen or KOLLAGEN => think of bones 🦴 => congenital SCOLIOSIS)
• ARTHROchalasia is COL IA (1st letter is A) and hence presents with severe JOINT hyper mobility.
• DERMATospARaxis is AR and a defective Procollagen-N-peptidase and presents with CUTIS laxa. (Cuties are Pros ;)

Step 2. For the Gene types, come down in descending order: 5 4 3 2 1 0 

Step 3. Remember Type V - DOEST NOT EXIST. 

Step 4. Revise again 😉

That's it! Stay safe 🌸

- Anagha :)

Types of COVID-19 antibody tests

Hi everyone! 

In this post, I will go over in very short the different types of  COVID-19 antibody tests.

Cancer Screening - US Preventive Services Task Force (USPSTF) guidelines

     As the saying goes - "Awareness is Power in a world where information is everywhere", lets quickly learn the USPSTF recommended guidelines for Cancer screening

CANCER	SCREENING MODALITY	AGE GROUP
Breast Cancer	Biennial Mammography	Women aged 50 to 74 yrs
Cervical Cancer	Cervical cytology every 3yrs   Cervical cytology every 3 yrs  or High risk HPV(hrHPV) testing every 5 yrs or hrHPV testing in combination with cytology every 5yrs (cotesting)	Women aged 21 to 29 yrs  Women aged 30 to 65 yrs
Lung Cancer	Annual Low dose CT chest (who have a 20 pack-year smoking history and currently smoke/quit within past 15 yrs)	Adults aged 50 to 80 yrs
Colorectal Cancer	Colonoscopy screening every 10 yrs Flexible sigmoidoscopy every 5 yrs Computed tomography colonography every 5 yrs High-sensitivity guaiac fecal occult blood test (HSgFOBT) or fecal immunochemical test (FIT) every yr Stool DNA-FIT every 1 to 3 yrs	Adults aged 45 to 75 yrs

P.S. - USPSTF now recommends screening for Colorectal cancer in adults aged 45 to 75 years

- Padma Sri Katikaneni                                                                                                                       

                  

Human herpes viruses (HHV) types mnemonic

Human herpes viruses mnemonic... In case you get them mixed up...

Fact of the day - Athlete's heart

Hi!

Athlete's heart - physiologic eccenteric hypertrophy (cardiac remodeling) - changes include resting bradycardia, higher cardiac output with exercise, dilatation of LV cavity size with hypertrophy of myocytes compared to normal heart.

vs pathologic hypertrophy in case of systolic heart failure, aortic/mitral regurgitation, dilated cardiomyopathy(DCM) (volume overload conditions).

LV systolic ejection fraction is normal - low-normal in athletes.

(vs HCM- high, DCM- low)

HCM is a common cause of death in athletes, especially those with family history.

That's all

- Jaskunwar Singh

METABOLIC SYNDROME - MNEMONIC

BE AWARE of THE HIGH SUGARS

(3 or more of the following : diagnosis of Metabolic syndrome)

Blood Pressure >/=130/85mmHg

Abdominal obesity ( waist circumference) > 40 inches in males; >35 inches in females

Triglycerides >/=150 mg/dl

HDL cholesterol < 40mg/dl in males; < 50mg/dl in females

Fasting blood Sugars >/=100mg/dl

Hope this helps:)

- Padma Sri Katikaneni

Megalencephaly mnemonic

Hello friends! 

Here's is the simple mnemonic to remember the important causes of Megalencephaly.

CATS

Canavan's disease

Alexander disease

Tay- Sachs disease

Sandoff disease.

That's all!

Dr.Madhuri Reddy

COMMON METASTASES - MNEMONICS

SITE OF METASTASIS                              PRIMARY TUMOUR 

BRAIN                                                                    Lots of Bad Stuff Kill microGlia

                                                                                 Lung, Breast, Skin (melanoma), Kidney, GI(colon)

LIVER                                                                     Cancer Sometimes Penetrates Big Liver   

                                                                                 Colon, Stomach, Pancreas, Breast, Lung 

BONE                                                                      Permanently Relocated Tumours Like Bones

                                                                                 Prostate, Renal, Thyroid, Lungs, Breast

     

P.S. - FOUR CARCINOMAS ROUTE HEMATOGENOUSLY! 

        (Follicular carcinoma thyroid, Choriocarcinoma, Renal cell carcinoma, Hepatocellular Carcinoma)

Hope these mnemonics help!

Feel free to add any more fun mnemonics :)

- Padma Sri Katikaneni

Internal Medicine residency program Excel sheet (2020)

Hi guys,

I am sharing an excel sheet containing 200+ Internal Medicine residency programs. Feel free to download it and edit the information and programs according to your profile and needs. There may be a few IMG friendly programs that are missing, so do your homework and don't apply blindly. Use this as a template sheet to work on!

Kindly note, the comments are subjective, and none of the authors endorse them as proven facts. Some information may be incorrect as a lot of manual labor went into making this sheet.

Hope this helps in making the ERAS application process easier!

https://docs.google.com/spreadsheets/d/1l2Vra6wDcZX5_FMLOFcetZua64wwNsdXKDKB0saGykg/edit?usp=sharing

HERPANGINA vs HERPETIC GINGIVOSTOMATITIS

	HERPANGINA (Hand-Foot-Mouth Disease)	HERPETIC GINGIVOSTOMATITIS
CAUSATIVE VIRUS	Coxsackie A virus	Herpes Simplex type 1 virus (HSV-1)
AGE	3-10 years	6 months-5 years
CLINICAL                             PRESENTATION	Grayish Vesicles on                Posterior Oropharynx      (soft palate, tonsils, tonsillar pillars, Uvula)	Clusters of vesicles on       Anterior Oropharynx (Lips, buccal mucosa, tongue, gingiva, hard palate)
TREATMENT	Supportive management with oral hydration and analgesics	Oral Acyclovir

Fact of the day - halothane hepatotoxicity

 Hi!

A patient with biliary stones who's undergone laparoscopic cholecystectomy may develop signs of hepatotoxicity between 2 days - three weeks post-op. due to halothane. The mechanism is this anesthetic's biotransformation to reactive metabolites through P450.

At risk category of patients are females more than 40 years of age.
Labs show elevated AST and ALT.
Hepatitis is relatively rare.

Other effects:

- Cardiac arrhythmias

- malignant hyperthermia

- hypertension


That's all

- Jaskunwar Singh

Levetiracetam - pregnancy considerations

 Hi!

Levetiracetam, used primarily for seizures control, is also used off-label for SAH, status epilepticus, seizure prophylaxis in craniotomy and traumatic brain injury.

Dosing is increased in pregnancy and closely monitored regularly due to various physiologic effects, especially in third trimester. (levitate dose of levetiracetam) :-

- increased volume of distribution, Vd (increase in plasma volume, CO)

- increased renal excretion (increase in GFR; levitate the rate)

- rapid and almost complete absorption via GIT  (unlike other drugs with decreased absorption in pregnancy)

- low risk of adverse effects and fetal malformations when used in monotherapy. (low with mono, high with poly)

- Levetiracetam is NOT metabolized by liver; Cyt P450 independent. Bioavailability 100%. (unlike other antiepileptics - hepatic metabolism increases in pregnancy)

Levetiracetam crosses placenta and can be detected in the newborn. (leve leaves mother)

The newborns are at greater risk of SGA and low APGAR score.

Protein-binding of the drug is low (<10%). So, decrease in albumin concentration during pregnancy does not significantly affect the drug concentration. (low pro)

That's all

- Jaskunwar Singh