# Clinical Cases: Behavioral and Developmental Disorders

## Case 1: Autism Spectrum Disorder

### Patient Demographics
- **Age:** 2-year-old male
- **Sex:** Male

### Chief Complaint
"He doesn't talk like other kids his age, and he's in his own world."

### History of Present Illness
A 2-year-old boy is brought to his pediatrician by his parents who are concerned about his development. He has only 3-4 words that he uses inconsistently and often just repeats words he hears (echolalia) rather than using them meaningfully. He does not point to objects to show his parents things he finds interesting. He rarely makes eye contact, even with his parents, and does not seem interested in other children at the park. He lines up his toy cars in perfect rows for extended periods and becomes very upset if anyone moves them. He flaps his hands when excited and walks on his toes frequently. He has an older sister who is developing normally. He reached motor milestones on time.

### Developmental History
- **Gross motor:** Sat at 6 months, walked at 12 months (on time)
- **Fine motor:** Appropriate for age
- **Language:** First words around 12 months, but vocabulary has not expanded; no two-word phrases
- **Social:** Never brought toys to show parents, no joint attention, does not respond to name consistently

### M-CHAT-R/F Screening (completed at 18 months)
- Score: 8/20 items positive (high risk)
- Follow-up interview confirmed concerns in multiple domains

### Physical Examination
- **General:** Active toddler, appears healthy, minimal eye contact with examiner
- **Growth:** Height 50th percentile, weight 55th percentile, head circumference 75th percentile
- **Neurologic:** Normal tone, strength, reflexes
- **Behavior observed:**
  - Does not respond when name is called
  - Lines up blocks repeatedly
  - Flaps hands when mother claps
  - Does not point or follow pointing
  - No pretend play observed
  - Becomes distressed when block tower is knocked over

### Diagnosis
**Autism spectrum disorder (ASD)**

### Clinical Reasoning
This child meets DSM-5 criteria for ASD with deficits in BOTH required domains:

**Social communication deficits:**
- Lack of joint attention (not pointing to share interest)
- Reduced eye contact
- Absent social referencing
- Delayed and abnormal language development
- Does not respond to name

**Restricted/repetitive behaviors (at least 2):**
- Stereotyped motor movements (hand flapping, toe walking)
- Insistence on sameness (distress when toys moved)
- Highly restricted interests (lining up cars)
- Possible sensory interests (not fully assessed)

Red flags present before age 2 include: no pointing by 12 months, no babbling or gesturing, loss of social engagement, and failure to respond to name. Early identification allows for early intensive intervention, which improves outcomes.

### Management
1. **Referral for comprehensive evaluation:** Developmental pediatrician or child psychologist for formal diagnosis
2. **Early intervention referral (Part C):** Immediate referral regardless of final diagnosis; do not wait for evaluation completion
3. **Applied Behavior Analysis (ABA) therapy:** Evidence-based intensive behavioral intervention (25+ hours/week ideal)
4. **Speech-language therapy:** Target functional communication; consider augmentative communication
5. **Occupational therapy:** Address sensory processing and fine motor skills
6. **Audiology evaluation:** Rule out hearing loss as contributing factor
7. **Genetic testing:** Consider chromosomal microarray and fragile X testing
8. **Family support:** Connect with autism support organizations and parent training

### Clinical Image
![Toddler demonstrating lack of joint attention](case_01_image.jpg)

**Image Description:** Illustration depicting the concept of joint attention (or lack thereof) in autism spectrum disorder, showing a child failing to follow a parent's pointing or share focus on objects of interest.

**Source:** Wikimedia Commons - Autism Awareness
**URL:** https://commons.wikimedia.org/wiki/File:Autism_symptoms.svg
**License:** CC BY-SA 4.0

---

## Case 2: Attention-Deficit/Hyperactivity Disorder

### Patient Demographics
- **Age:** 8-year-old male
- **Sex:** Male

### Chief Complaint
"His teacher says he can't sit still and isn't finishing his work."

### History of Present Illness
An 8-year-old boy is brought by his parents after receiving concerning reports from his third-grade teacher. The teacher notes that he is constantly fidgeting, leaves his seat frequently, talks excessively, and often blurts out answers without raising his hand. He rarely completes assignments in class and seems to "zone out" during lessons. At home, parents describe him as always "on the go" and note he has difficulty following through on chores and loses things constantly (homework, shoes, sports equipment). He is described as bright but "not living up to his potential." These behaviors have been present since kindergarten but are now more problematic with increasing academic demands. He sleeps well (9 hours/night) and has no history of trauma.

### Developmental History
- **Milestones:** All achieved on time
- **Academic history:** Bright child, reading and math skills appropriate when he focuses
- **Social:** Has friends but sometimes struggles due to interrupting and not waiting his turn

### ADHD Evaluation

**Parent Rating Scale (Vanderbilt):**
- Inattentive symptoms: 7/9 items rated "often" or "very often"
- Hyperactive-impulsive symptoms: 8/9 items rated "often" or "very often"
- Symptoms present for >6 months, causing impairment

**Teacher Rating Scale (Vanderbilt):**
- Inattentive symptoms: 8/9 items rated "often" or "very often"
- Hyperactive-impulsive symptoms: 7/9 items rated "often" or "very often"
- Performance significantly affected

### Physical Examination
- **Vital Signs:** HR 88 bpm, BP 100/62 mmHg, Height 75th percentile, Weight 50th percentile
- **General:** Active boy, difficulty sitting still during interview, frequently interrupts
- **Cardiovascular:** Regular rhythm, no murmurs
- **Neurologic:** Normal

### Diagnosis
**Attention-deficit/hyperactivity disorder, combined presentation**

### Clinical Reasoning
This child meets DSM-5 criteria for ADHD, combined presentation:
- **Inattention (6+ symptoms):** Fails to give close attention, difficulty sustaining attention, does not follow through on tasks, difficulty organizing, avoids sustained mental effort, loses things, easily distracted, forgetful
- **Hyperactivity-Impulsivity (6+ symptoms):** Fidgets, leaves seat, runs/climbs inappropriately, difficulty playing quietly, "on the go," talks excessively, blurts out answers, difficulty waiting turn, interrupts

Additional criteria met:
- Symptoms present before age 12 (since kindergarten)
- Symptoms present in 2+ settings (home AND school)
- Clear functional impairment (academic underperformance, social difficulties)
- Not better explained by another disorder

Normal sleep history and absence of trauma make other explanations less likely. Academic abilities are intact, ruling out learning disability as primary cause.

### Management
1. **Medication:** Methylphenidate extended-release starting dose 18-27 mg every morning (first-line for children 6+ years)
2. **Behavioral therapy:** Parent training in behavior management; classroom behavioral interventions
3. **Educational support:** 504 plan or IEP evaluation for classroom accommodations (preferential seating, extended time, chunked assignments)
4. **Monitoring:** Follow-up in 2-4 weeks for medication titration; check height, weight, BP, HR at each visit
5. **Side effect counseling:** Discuss appetite suppression, sleep difficulties; give medication with breakfast, consider drug holidays if growth concerns
6. **School collaboration:** Regular communication with teacher; repeat rating scales to monitor response

### Clinical Image
![Child demonstrating hyperactive behavior in classroom](case_02_image.jpg)

**Image Description:** Illustration of a child with ADHD in a classroom setting, showing characteristic behaviors including difficulty remaining seated, fidgeting, and appearing distracted while classmates are focused.

**Source:** Wikimedia Commons
**URL:** https://commons.wikimedia.org/wiki/File:ADHD-3.svg
**License:** CC BY-SA 4.0

---

## Case 3: Global Developmental Delay

### Patient Demographics
- **Age:** 18-month-old female
- **Sex:** Female

### Chief Complaint
"She's not walking or talking like her older brother did."

### History of Present Illness
An 18-month-old girl is brought to her pediatrician because her parents are concerned about her development. She is not yet walking independently and only pulls to stand with support. She has no words and babbles infrequently. She does not point or wave bye-bye. She can pick up small objects but has difficulty with a pincer grasp. Her parents note she is less interactive than her brother was at this age. She was born full-term without complications. There is no family history of developmental delays. She has had recurrent ear infections and is scheduled for myringotomy tubes.

### Developmental Assessment (Ages and Stages Questionnaire at 18 months)

| Domain | Score | Status |
|--------|-------|--------|
| Gross Motor | 20 | Below cutoff |
| Fine Motor | 30 | Below cutoff |
| Communication | 15 | Below cutoff |
| Problem-solving | 25 | Below cutoff |
| Personal-social | 30 | At cutoff |

### Physical Examination
- **Vital Signs:** Weight 25th percentile, Length 30th percentile, Head circumference 15th percentile
- **General:** Quiet infant, makes some eye contact
- **HEENT:** Bilateral middle ear effusions
- **Cardiovascular:** Normal
- **Neurologic:** Mild central hypotonia; pulls to stand with support, not walking; age-appropriate reflexes

### Additional Workup
- **Audiology:** Moderate conductive hearing loss bilaterally (consistent with chronic effusions)
- **Thyroid function:** TSH 5.2 mIU/L (normal)
- **Lead level:** 2 mcg/dL (normal)
- **Chromosomal microarray:** Pending

### Diagnosis
**Global developmental delay (delays in 2 or more domains in a child under 5 years)**

### Clinical Reasoning
This child has significant delays in multiple developmental domains (gross motor, fine motor, language, cognitive), meeting criteria for global developmental delay. While her hearing loss likely contributes to language delay, it does not explain delays in motor and cognitive domains. The combination of microcephaly (head circumference 15th percentile with height/weight higher), hypotonia, and global delays suggests an underlying etiology that should be investigated. The differential includes genetic conditions (chromosomal abnormalities, single gene disorders), metabolic disorders, and structural brain abnormalities. The distinction between "developmental delay" (used in children under 5) and "intellectual disability" (requires formal cognitive testing, usually after age 5) is important.

### Management
1. **Early intervention referral (Part C):** Immediate referral for comprehensive developmental services
2. **Audiology treatment:** Proceed with myringotomy tubes; reassess hearing after
3. **Genetic testing:**
   - Chromosomal microarray (first-line for unexplained developmental delay)
   - Fragile X testing
   - Additional genetic testing based on microarray results
4. **Brain MRI:** Evaluate for structural abnormalities given microcephaly
5. **Metabolic screening:** Consider if MRI and genetic testing unrevealing
6. **Therapy services:**
   - Physical therapy for gross motor delays
   - Occupational therapy for fine motor delays
   - Speech-language therapy for communication
7. **Close follow-up:** Serial developmental assessments to monitor progress
8. **Family support:** Genetic counseling, parent support groups

### Clinical Image
![Developmental milestones chart showing delays](case_03_image.jpg)

**Image Description:** Developmental milestone chart comparing expected milestone acquisition ages with delayed patterns, illustrating the concept of global developmental delay affecting multiple domains simultaneously.

**Source:** Wikimedia Commons - CDC Milestones
**URL:** https://commons.wikimedia.org/wiki/File:Developmental_milestones.svg
**License:** Public Domain