Internal medicine

IgG4-Related Hypophysitis: The Great Mimicker of Pituitary Adenoma A State-of-the-Art Review for the Discerning Clinician Dr Neeraj Manikath , claude.ai Abstract IgG4-related hypophysitis (IgG4-RH) represents one of the most compelling diagnostic challenges in contemporary endocrinology and neurosurgery. This immune-mediated inflammatory condition affecting the pituitary gland masterfully mimics non-functioning pituitary adenomas, frequently leading to misdiagnosis and unnecessary surgical intervention. As part of the broader IgG4-related disease (IgG4-RD) spectrum, this condition demands heightened clinical suspicion, particularly in patients presenting with sellar masses, hypopituitarism, and concomitant systemic manifestations. This comprehensive review synthesizes current evidence on epidemiology, pathophysiology, clinical presentation, diagnostic criteria, and management strategies, while highlighting critical "pearls" that distinguish this steroid-responsive conditi...

  Thyroid Hormone Resistance: Distinguishing Pituitary-Selective from Generalized Resistance—A Clinical and Molecular Paradigm Dr Neeraj Manikath , claude.ai Abstract Resistance to thyroid hormone (RTH) represents a rare endocrine disorder characterized by reduced tissue responsiveness to thyroid hormone action, resulting in the paradoxical biochemical pattern of elevated free thyroxine (FT4) with non-suppressed thyroid-stimulating hormone (TSH). While the syndrome was first described over six decades ago, the critical distinction between pituitary-selective resistance (PRTH) and generalized resistance (GRTH) remains underappreciated in clinical practice, yet carries profound therapeutic implications. This review examines the molecular basis, diagnostic strategies, and treatment paradigms for these two phenotypic variants, with emphasis on practical clinical pearls that can prevent catastrophic management errors. Introduction The syndrome of resistance to thyroid hormone affect...

  Heparin-Induced Thrombocytopenia without Thrombocytopenia: The Paradoxical Presentation That Challenges Diagnostic Paradigms Dr Neeraj Manikath , claude.ai Abstract Heparin-induced thrombocytopenia (HIT) represents one of the most serious adverse drug reactions in hospital medicine, traditionally characterized by thrombocytopenia and paradoxical thrombosis. However, a subset of patients develops the prothrombotic complications of HIT while maintaining platelet counts above 150 × 10⁹/L or experiencing drops of less than 50% from baseline. This variant, termed "HIT without thrombocytopenia" or "normocytopenic HIT," challenges our diagnostic algorithms and represents a diagnostic blind spot in contemporary practice. This review explores the pathophysiology, clinical recognition, diagnostic approach, and management of this underrecognized entity. Introduction The classical teaching of HIT emphasizes the triad of thrombocytopenia, heparin exposure, and thrombosis. ...

  The Gut-Brain Axis of Parkinson's Disease: Alpha-Synuclein Origination Theory A Paradigm Shift in Understanding Parkinson's Disease Pathogenesis Dr Neeraj Manikath , claude.ai Abstract Parkinson's disease (PD) has traditionally been conceptualized as a central nervous system disorder originating in the substantia nigra. However, emerging evidence supports a revolutionary hypothesis: PD pathology may originate in the enteric nervous system (ENS) and propagate rostrally via the vagus nerve to the brain. This "gut-first" theory explains the decades-long prodromal phase characterized by gastrointestinal dysfunction, anosmia, and REM sleep behavior disorder (RBD)—symptoms that often precede classic motor manifestations by 10-20 years. For internists, this paradigm shift is transformative: patients presenting with this constellation of seemingly unrelated "functional" complaints may be harboring early neurodegeneration. This review synthesizes the pathoph...