Overview Snapshot A 19-year-old female presents with chronic fatigue. She reports feeling very sleepy throughout the day, has been told that she would doze off, and then eventually drop her head on to the desk. She notes periods of not being able to move after waking up and fell to the ground after being excited at the news of her sister’s pregnancy. What frightened her the most are the vivid “visions” she would get when she is about to fall asleep. Sleep Stages Sleep Stage Description EEG Waveform Awake and alert Beta Awake and eyes closed Alpha Stage N1 Light sleep Theta Stage N2 Deeper sleep Sleep spindles and K complexes Stage N3 Deepest non-REM sleep Sleepwalking Night terrors Bedwetting Delta REM Dreaming Beta Suprachiasmastic nucleus of the hypothalamus is involved in circadian rhythm regulation GABA agonists (alcohol, benzodiazepines, and barbiturates) reduce REM and delta sleep REM Sleep Description dreaming loss of motor tone may serve a memory processing function Physiology same EEG pattern as when awake therefore called "paradoxical sleep" or "desynchronized sleep" rapid eye movement defining feature of REM sleep due to activity of paramedian pontine reticular formation erection ↑ and variable pulse and blood pressure loss of muscle tone Neurotransmitters acetylcholine is the principle neurotransmitter norepinephrine, serotonin, and histamine suppress REM sleep therefore, certain antidepressants (eg, SSRI, SNRI) can pharmacologically suppress REM sleep Timing occurs every 90 min duration ↑ with every cycle amount of REM sleep ↓ with age Sleep Disorders Narcolepsy disordered regulation of sleep cycles secondary to loss of orexin (hypocretin) neuropeptides excessive daytime sleepiness sleep paralysis may include hallucinations hypnagogic just before sleep hypnopompic just before awakening nocturnal and narcoleptic sleep episodes start off with REM sleep cataplexy loss of all muscle tone following a strong emotional stimulus only some patients patients have undetectable hypocretin-1 in levels in CSF stong genetic component treat with stimulants e.g., modafinil (first-line) and amphetamines (generally second-line) Sleep apnea see Sleep Apnea
QUESTIONS 1 of 6 1 2 3 4 5 6 Previous Next Lab Values Blood Hematologic Cerebrospinal Sweat, Urine, and BMI Blood, Plasma, Serum Reference Range ALT 8-20 U/L Amylase, serum 25-125 U/L AST 8-20 U/L Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL Calcium, serum (Ca2+) 8.4-10.2 mg/dL Cholesterol, serum Rec: < 200 mg/dL Cortisol, serum 0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h Creatine kinase, serum Male: 25-90 U/LFemale: 10-70 U/L Creatinine, serum 0.6-1.2 mg/dL Electrolytes, serum Sodium (Na+) 136-145 mEq/L Chloride (Cl-) 95-105 mEq/L Potassium (K+) 3.5-5.0 mEq/L Bicarbonate (HCO3-) 22-28 mEq/L Magnesium (Mg2+) 1.5-2.0 mEq/L Estriol, total, serum (in pregnancy) 24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL 28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL Ferritin, serum Male: 15-200 ng/mLFemale: 12-150 ng/mL Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250 pH 7.35-7.45 PCO2 33-45 mmHg PO2 75-105 mmHg Glucose, serum Fasting: 70-110 mg/dL2-h postprandial:<120 mg/dL Growth hormone - arginine stimulation Fasting: <5 ng/mLProvocative stimuli: > 7ng/mL Immunoglobulins, serum IgA 76-390 mg/dL IgE 0-380 IU/mL IgG 650-1500 mg/dL IgM 40-345 mg/dL Iron 50-170 μg/dL Lactate dehydrogenase, serum 45-90 U/L Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL Osmolality, serum 275-295 mOsmol/kd H2O Parathyroid hormone, serume, N-terminal 230-630 pg/mL Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L Phosphorus (inorganic), serum 3.0-4.5 mg/dL Prolactin, serum (hPRL) < 20 ng/mL Proteins, serum Total (recumbent) 6.0-7.8 g/dL Albumin 3.5-5.5 g/dL Globulin 2.3-3.5 g/dL Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h Thyroxine (T4), serum 5-12 μg/dL Triglycerides, serum 35-160 mg/dL Triiodothyronine (T3), serum (RIA) 115-190 ng/dL Triiodothyronine (T3) resin uptake 25%-35% Urea nitrogen, serum 7-18 mg/dL Uric acid, serum 3.0-8.2 mg/dL Hematologic Reference Range Bleeding time 2-7 minutes Erythrocyte count Male: 4.3-5.9 million/mm3Female: 3.5-5.5 million mm3 Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/hFemale: 0-20 mm/h Hematocrit Male: 41%-53%Female: 36%-46% Hemoglobin A1c ≤ 6 % Hemoglobin, blood Male: 13.5-17.5 g/dLFemale: 12.0-16.0 g/dL Hemoglobin, plasma 1-4 mg/dL Leukocyte count and differential Leukocyte count 4,500-11,000/mm3 Segmented neutrophils 54%-62% Bands 3%-5% Eosinophils 1%-3% Basophils 0%-0.75% Lymphocytes 25%-33% Monocytes 3%-7% Mean corpuscular hemoglobin 25.4-34.6 pg/cell Mean corpuscular hemoglobin concentration 31%-36% Hb/cell Mean corpuscular volume 80-100 μm3 Partial thromboplastin time (activated) 25-40 seconds Platelet count 150,000-400,000/mm3 Prothrombin time 11-15 seconds Reticulocyte count 0.5%-1.5% of red cells Thrombin time < 2 seconds deviation from control Volume Plasma Male: 25-43 mL/kgFemale: 28-45 mL/kg Red cell Male: 20-36 mL/kgFemale: 19-31 mL/kg Cerebrospinal Fluid Reference Range Cell count 0-5/mm3 Chloride 118-132 mEq/L Gamma globulin 3%-12% total proteins Glucose 40-70 mg/dL Pressure 70-180 mm H2O Proteins, total < 40 mg/dL Sweat Reference Range Chloride 0-35 mmol/L Urine Calcium 100-300 mg/24 h Chloride Varies with intake Creatinine clearance Male: 97-137 mL/minFemale: 88-128 mL/min Estriol, total (in pregnancy) 30 wks 6-18 mg/24 h 35 wks 9-28 mg/24 h 40 wks 13-42 mg/24 h 17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 hFemale: 2.0-8.0 mg/24 h 17-Ketosteroids, total Male: 8-20 mg/24 hFemale: 6-15 mg/24 h Osmolality 50-1400 mOsmol/kg H2O Oxalate 8-40 μg/mL Potassium Varies with diet Proteins, total < 150 mg/24 h Sodium Varies with diet Uric acid Varies with diet Body Mass Index (BMI) Adult: 19-25 kg/m2 Calculator ( ) xy AC 7 8 9 ÷ 4 5 6 × 1 2 3 - 0 . = + Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.NE.4754) A mother brings her 7-year-old son to the pediatrician because she is worried about his sleep. She reports that the child has repeatedly woken up in the middle of the night screaming and thrashing. Although she tries to reassure the child, he does not respond to her or acknowledge her presence. Soon after she arrives, he stops screaming and appears confused and lethargic before falling back asleep. When asked about these events, the child reports that he cannot recall ever waking up or having any bad dreams. These events typically occur within four hours of the child going to sleep. The child’s past medical history is notable for asthma and type I diabetes mellitus. He uses albuterol and long-acting insulin. There have been no recent changes in this patient’s medication regimen. His family history is notable for obesity and obstructive sleep apnea in his father. Physical examination reveals a healthy male at the 40th and 45th percentiles for height and weight, respectively. Which of the following EEG waveforms is most strongly associated with this patient’s condition? Review Topic QID: 108961 1 Alpha waves 9% (7/82) 2 Beta waves 11% (9/82) 3 Theta waves 12% (10/82) 4 Delta waves 56% (46/82) 5 Sleep spindles 10% (8/82) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (M1.NE.4671) A 23-year-old woman is seen by her primary care physician. The patient has a several year history of excessive daytime sleepiness. She also reports episodes where she suddenly falls to the floor after her knees become weak, often during a laughing spell. She has no other significant past medical history. Her primary care physician refers her for a sleep study, which confirms the suspected diagnosis. Which of the following laboratory findings would also be expected in this patient? Review Topic QID: 107139 1 Increased serum methoxyhemoglobin 0% (0/14) 2 Reduced serum hemoglobin 0% (0/14) 3 Undetectable CSF hypocretin-1 93% (13/14) 4 Increased CSF oligoclonal bands 0% (0/14) 5 Increased serum ESR 0% (0/14) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 3 (M1.NE.73) An 18-year-old man presents to his primary care physician with a complaint of excessive daytime sleepiness. He denies any substance abuse or major changes in his sleep schedule. He reports frequently dozing off during his regular daily activities. On further review of systems, he endorses falling asleep frequently with the uncomfortable sensation that there is someone in the room, even though he is alone. He also describes that from time to time, he has transient episodes of slurred speech when experiencing heartfelt laughter. Vital signs are stable, and his physical exam is unremarkable. This patient is likely deficient in a neurotransmitter produced in which part of the brain? Review Topic QID: 106599 1 Thalamus 15% (22/149) 2 Pons nucleus 7% (11/149) 3 Hippocampus 24% (36/149) 4 Hypothalamus 40% (60/149) 5 Midbrain 9% (13/149) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (M1.NE.75) A 19-year-old man is seen by his primary care physician. The patient has a history of excessive daytime sleepiness going back several years. He has begun experiencing episodes in which his knees become weak and he drops to the floor when he laughs. He has a history of marijuana use. His family history is notable for hypertension and cardiac disease. His primary care physician refers him for a sleep study, and which confirms your suspected diagnosis. Which of the following is the best first-line pharmacological treatment for this patient? Review Topic QID: 106858 1 Dextroamphetamine 0% (0/17) 2 Lisdexamfetamine 6% (1/17) 3 Methylphenidate 12% (2/17) 4 Zolpidem 18% (3/17) 5 Modafinil 65% (11/17) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (M1.NE.129) A mother brings her 6-year-old daughter to the pediatrician to discuss her child's sleeping troubles. Three times now in the last month the child has begun screaming and crying in the middle of the night. When the parents rush to the child's room, they find her crying inconsolably. They try to ask her what is wrong, but she does not respond and persists crying for approximately 20 minutes, after which she goes back to sleeping comfortably. Upon awaking the following morning, she has no recollection of the night's events. Which of the following is true about these episodes? Review Topic QID: 105799 1 They will be persistent into adulthood 0% (0/14) 2 They occur only during non-REM sleep 93% (13/14) 3 They can occur any time during the sleep cycle 0% (0/14) 4 They are associated with child abuse 0% (0/14) 5 They are associated with later development of a mood disorder 7% (1/14) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 2