Mygale lasiodora

Prepared by trituration of the dried whole spider (a New World tarantula; family Theraphosidae) followed by serial attenuation. Classical sources attribute to the crude animal a neuro-excitatory influence culminating in violent, inco-ordinate muscular movements, facial grimacing, and incessant restlessness, which became the keynote clinical sphere in chorea (St. Vitus’ dance) and allied hyperkinesias [Hering], [Allen], [Clarke]. The taxonomic name “Mygale lasiodora” reflects nineteenth-century nomenclature; modern arachnology recognises Lasiodora spp., but homeopathic literature preserves Hering’s form [Clarke]. Folklore of “tarantism” belongs chiefly to Lycosa/Tarentula hispanica (a distinct remedy); Mygale represents a New World tarantula line with less dramatic music-ecstasy colouring and a plainer motor cortex/spinal hyper-irritability signature [Hering], [Farrington].

Data are largely clinical with fragmentary provings; Hering introduced the remedy, Allen collated case material, and Clarke/Boericke summarised keynotes: incessant, purposeless movements of face and limbs, sudden jerks, grimacing, tongue darting, inability to keep still while awake, and movements ceasing in sleep; right-sided chorea is repeatedly noted [Hering], [Allen], [Clarke], [Boericke]. Tags: [Clinical] [Proving].

The essence of Mygale lasiodora is a wake-driven chorea: a child (or adolescent) who cannot keep still while awake—face twisting, tongue darting, hands flinging, feet tapping or stamping—yet who lies perfectly quiet in sleep. The movements are inco-ordinate, purposeless, often right-sided, and explode under emotion, contradiction, observation, and voluntary effort. The will’s attempt to command produces a counter-jerk, so the act of eating, writing, or speaking—especially with onlookers—magnifies the storm. The mental portrait is less theatrical than Tarentula; there is no marked love of music or erotic playfulness. Instead we see simple excitability, shame at loss of control, and relief in quiet, cool rooms and unobserved spaces ([Better For]). The sleep–wake switch is the master-key: movements stop completely in sleep and reappear on waking, a clinical rule of thumb that, when present with facial grimacing and darting tongue, points with certainty to Mygal. over Agaricus (more frolicsome, chilly, musical), Zincum (fidgety, depressed, evening-worse), and Cuprum (cramp and suppression rather than scatter).

Pathophysiologically the picture reads as cortical–striatal disinhibition with hyperkinesia, precipitated by affective arousal; the patient’s performance-worse axis is an external handle on that circuitry. Nursing measures—cool air, reduced audience, firm but gentle support to a limb during tasks, and spacing of efforts—accord with remedy modalities and often reveal the diagnosis at bedside. In practice, Mygal. has shone in post-infectious chorea (measles/scarlatina convalescence), pubertal chorea in girls with menses-worse, and schoolchildren whose handwriting and mealtimes are wrecked by sudden flings. Prescribe it when the triad stands out: sleep abolishes the movements, right-sided scatter of face/hand/foot with darting tongue, and worse from excitement, observation, and intent; then watch intervals of calm lengthen and the child’s will rejoin the body [Hering], [Allen], [Clarke], [Farrington].

• Motor cortex & pyramidal outflow — Explosive, inco-ordinate discharges producing choreic tossings, grimaces, and jerks; movements stop during sleep (central signature) [Hering], [Allen].
• Face & buccal muscles — Distortion of features, darting tongue, biting of cheeks/tongue, grimacing that hinders speech and feeding [Clarke], [Allen].
• Upper extremities (often right) — Rapid, incessant motions; cannot hold objects; handwriting impossible; right arm commonly first and worst [Hering], [Boger].
• Lower extremities — Kicking, dancing, feet constantly in motion; cannot walk in a straight line; falls from sudden knee-jerks [Allen], [Boericke].
• Speech & deglutition (bulbar synchrony) — Words broken by facial twitching; chorea of the tongue and throat; choking on attempts to swallow during paroxysms [Clarke].
• Sleep–wake switch — Complete suspension of movements in sleep with renewal on waking; a diagnostic keynote to separate from simulants and from some tics [Hering], [Clarke].
• Emotional triggers — Excitement, contradiction, fright, and observation exacerbate movements (performance-worse); child steadies when left alone [Allen], [Farrington].
• Menstrual/sexual axis (minor) — Chorea intensifies at puberty, during menses, or from uterine disturbance in girls (compare Tarent., Sep., Lil-t.) [Clarke], [Farrington].

The mental field is reactive and excitable, with emotions acting like sparks to the motor powder—anger, contradiction, or being watched instantly drive the limbs into wilder capers [Allen]. The child is bright but impulsive, changeable, and cannot sustain attention while the movements surge; attempts at self-control multiply the very jerks he would suppress, a paradox repeatedly observed at the bedside [Hering]. Shame at loss of control alternates with giggling restlessness; he may hide his hands or sit upon them, reflecting the partial help from firm support (see Better For) [Farrington]. There is fear after fright with renewal of choreic storms, and a tendency to dramatise ailments less than in Tarentula, which craves music and theatrics; Mygal. is simpler—a body jerking faster than the will [Clarke]. Speech becomes chopped by facial grimaces and tongue thrusts, and the child snaps answers lest the next jerk steal the words. Sleep brings a merciful oblivion, with movements wholly suspended, and the morning finds hope until the first effort starts the cascade anew—this cycle ties mind to the sleep–wake axis already noted (Affinities/Modalities). Irritability comes from frustration rather than malice; tenderness and calm surroundings lessen the storm, confirming the performance-worse motif [Allen].

Sleep is the remedy’s balm: all movements cease; the child lies quiet, breath deepens, and the face relaxes [Hering], [Clarke]. First waking re-ignites the storm; if left unhurried and unobserved, the onset is milder, confirming the quiet/unobserved better modality. Dreams are lively but seldom remembered; talking in sleep is rare because the motor explosion belongs to wakefulness. Daytime dozes (microsleeps) may briefly halt a flurry.

Dreams of school examinations or being laughed at preface a heavy choreic day; fright-dreams are followed by morning exacerbation (emotion-worse link) [Allen]. Pleasant dreams correlate with a calmer next morning, suggesting the mind’s share in the motor threshold. Erotic dreaming in adolescents has little prescribing value unless it synchronises with menses-worse chorea in girls.

Mygale lasiodora expresses a wakeful chorea: incessant, purposeless, right-leaning jerks and grimaces that vanish in sleep, only to restart on waking, worse from excitement, observation, contradiction, and voluntary effort, better in quiet, cool air, and when unobserved [Hering], [Allen], [Clarke]. The motor field includes face, tongue, hands, and feet, sabotaging speech, feeding, writing, and gait; firm support or pressure can momentarily steady a part. The picture suits post-infectious chorea (after measles/scarlatina), pubertal/menses chorea in girls, and hysterical colouring where emotion sparks storms. Distinguish from Tarentula hispanica (loves music/dance, mischievous, theatrical; often better dancing), Agaricus (frolicsome, musical chorea with chilliness and spinal signs), Zincum (fidgety feet, mental dulness, evening aggravation), Cuprum (clonic spasms, cramps, suppression rather than ceaseless scatter), Stramonium (violent spasms with terror and light-worse), and Hyoscyamus (silliness, lasciviousness with twitches) [Farrington], [Boger], [Kent]. The sleep–wake switch and performance-worse axis are the decisive clinical levers.

Slight evening heat after a day’s exertions, with head hot in warm, close rooms; temperature mostly normal; chorea is functional, not pyrexial [Clarke]. Fever, when present from intercurrent illness (measles/scarlatina convalescence), becomes the aetiologic backdrop for post-infectious chorea responsive to Mygal. if the keynote cluster is present [Allen], [Dewey].

Chill after exhaustion; heat of head with close rooms; sweat follows paroxysms on scalp and neck without relief of restlessness until sleep arrives [Clarke]. Sweating is a by-product of exertion, not a guiding symptom.

Head is thrown back and sideways by sudden, capricious jerks; the scalp heats in close rooms and cool air relieves, a simple nursing cross-link to the modalities [Clarke]. Vertex seems drawn upward by an invisible string; the occiput raps the pillow in a series of involuntary knocks during wakeful periods. Effort to hold the head still increases the amplitude of the next fling—intention-worse (see Worse For). Headache is dull, bruised, and follows prolonged paroxysms; it lessens if sleep comes soon after. Children bump the forehead on desks when a facial grimace spreads into a whole-body fling; small ecchymoses betray the violence of the day. There is no fixed aura; paroxysms arise from emotional spark or on waking. Compared with Agaricus, whose head movements are frolicsome and musical, Mygal. is abrupt, jagged, and exhausting [Farrington], [Boger].

Lids twitch; canthi quiver; there are rapid, purposeless saccadic deviations that blur reading lines [Allen]. Photophobia in bright rooms corresponds to sensory-overload worse, and the child prefers shade. Tears appear from effort and shame rather than pain; blinking is quick and fidgety. Convergence fails intermittently during jerks, so letters double and the book is thrown aside. Unlike Tarentula, ocular unrest shows little playfulness; it is a by-product of general motor storm.

Sudden startles to noise; a dropped book or sharp call explodes the limbs into fresh inco-ordination [Clarke]. There is no special otalgia; itch to rub the auricle appears when the hands seek occupation between spurts. Music does not notably soothe as it may in Tarentula; at times rhythm helps brief focus, but generally noise aggravates [Farrington].

Nasal twitching with grimacing pulls the nostrils; sniffing is frequent and involuntary. Odours in a warm schoolroom irritate and coincide with increase of facial movements. Epistaxis is uncommon but may follow a day of head-banging; blood is bright and scant; movements subside after sleep [Clarke].

The face is the dial of the storm: contortions, pouting, sudden smiles without joy, tongue darting between lips, and biting of cheeks/tongue mark meals and lessons [Allen]. Attempts to compose the features immediately summon a more grotesque counter-gesture, illustrating attempted control worse (Worse For). Saliva may be spattered by a snapped grimace; embarrassment deepens the sequence. In severe cases the features are in constant micro-motion while awake, ceasing in sleep—a hard line between day and night that helps the prescriber distinguish Mygal. from simulation [Hering], [Clarke].

Biting of the tongue and buccal mucosa accompanies inco-ordinate mastication; the tongue darts like a snake and withdraws unwilled [Allen]. Speech stumbles—consonants explode, vowels are clipped by a jerk. Appetite is capricious; the child cannot carry food steadily to the mouth, dropping spoonfuls by a final fling. Mouth heat in warm rooms provokes thirst for small cool sips; better in fresh air (cross-link Modalities).

Teeth click together during facial snaps; grinding may occur at the peak of excitement and abates in sleep. Jaw tires from repeated effort to clamp movements; tenderness at the temporomandibular region follows a day’s grimacing. Dental injury occurs when a jerk meets a hard utensil; care in feeding is required.

Swallowing is interrupted by a throat spasm or a facial tug; liquids dribble when a jerk coincides with a sip [Clarke]. Spasmodic gulping noises appear at the height of excitement; better when unobserved and in a quiet room (Better For). There is no membranous pathology; difficulties are mechanical and choreic.

Breathing is jerky; intercostals twitch; a sigh follows a flurry as the thorax re-coordinates. Voice breaks over syllables, with a cough-like expulsion during facial snaps [Allen]. Palpitation belongs to fright and exertion more than to cardiac disease; calm and cool air steady the pulse (Better For).

Palpitations occur with emotional sparks; pulse quickens during displays and settles in quiet. There is no fixed organic lesion; function follows the motor storm. Compare Agaricus (flutter with laughing excitability) and Stramonium (violence with terror) [Farrington], [Kent].

Short breaths in spurts, then a deep compensatory inspiration. Crowded rooms and heat increase unrest; open windows diminish it (modalities). Asthma is not a feature; breathlessness is choreic, not bronchial.

Appetite vacillates with fatigue; effort to eat aggravates movements by attention to the act (performance-worse) [Allen]. Nausea arises from over-exertion and heat; better by a pause at an open window. Hiccough may punctuate paroxysms. There is no specific gastritis; the sphere is functional.

Abdominal wall jerks accompany limb tossings; stitches occur in the right hypochondrium after long bouts of movement. Clothing bands are irksome during excitement; loosening relieves irritability (nursing measure). Colic from swallowed air or hasty eating subsides with rest.

Involuntary clenching relaxes after exertion; stool can be delayed but is hurried by excitement. A day of flurries ends in tired, sluggish bowels; constipation alternates with stool urging during school anxiety. There is no haemorrhoidal signature; rectal notes are secondary to nervous strain.

Urgency arises momentarily after a violent paroxysm; children may spill a few drops when a sudden jerk breaks control, then void normally [Clarke]. Enuresis is not typical; nocturnal continence is good when movements are absent—cross-link with better during sleep.

Desire for cool drinks during heat of effort; warm, crowded mealtimes are worst—attention on eating exacerbates inco-ordination (performance-worse) [Allen], [Clarke]. Thirst small and frequent. Appetite adequate but intake limited by mechanics.

Not characteristic. In adolescents, erotic dreams may punctuate active phases, but sexual sphere is rarely decisive for prescription in this remedy [Clarke].

Puberty and menses aggravate chorea—movements and facial grimacing increase before and during the flow; emotional lability rises with it [Clarke], [Farrington]. Chorea gravidarum has been noted in case reports benefiting from Mygal. when the sleep-stops keynote is present and observation/excitement worsen [Allen] [Clinical]. Distinguish from Tarentula when music markedly soothes or excites.

Cervico-dorsal muscles jerk the head; trapezius twitches throw books from the shoulder [Allen]. Lumbosacral ache follows a day of kicks and stamps; better after sleep and a cool sponge. Spinal tenderness is absent; fatigue, not inflammation, explains the soreness.

This is a capital sphere: hands fidget without rest, fingers dart and clutch nothing; right arm is often the first and worst, the spoon flung away as it nears the lips [Hering], [Boger]. Legs cannot be kept still—feet tapping, stamping, dancing; the gait is zigzag; efforts to walk straight end in a whirl or a fall. Voluntary effort aggravates—trying to thread a needle brings an extravagant fling; when unobserved, movements soften (cross-link Mind/Modalities) [Allen]. Sleep abolishes them. Distinguish from Zincum (fidgety feet, twitching with mental depression) and Cuprum (clonic spasms with cramp and suppression of movements rather than incessant scatter) [Farrington], [Boericke].

Bruises over shins, elbows, and forehead betray collisions from sudden jerks. Sweaty hands during performance-worse states; skin warm in close rooms. No toxic eruption signature belongs here; integument signs are traumatic.

Chorea / Hyperkinesia (motor pattern & triggers)

• Tarentula hispanica — Impulsive, cunning, music/dance ameliorate; sensual, theatrical; Mygal. is simpler, less erotic, sleep-stops and observation-worse [Farrington], [Clarke].
• Agaricus — Merry, musical jerks, frost-like twitchings, chilly; spinal pains; Mygal. jerks are abrupt, exhausting, and right-sided bias [Boger], [Farrington].
• Zincum metallicum — Fidgety feet, restless legs, mental depression; evening aggravation; Mygal. shows daytime performance-worse with facial grimace [Kent].
• Cuprum metallicum — Cramps, clonic spasms, suppression/ arrest of movement; cyanosis; Mygal. is incessant scatter, no cramp-core [Farrington].
• Stramonium — Violent spasms with terror, light and bright objects worse; mental fury outstrips motor; Mygal. less delirious, more purely motor [Kent].
• Hyoscyamus — Silliness, lasciviousness with twitching; Mygal. lacks marked sexual humour; has sleep-stop keynote [Clarke].
• Cicuta virosa — Opisthotonic spasms, injuries of head; convulsions rather than chorea; Mygal. movements are partial, incessant, not tetanic [Boger].
• Ignatia — Hysterical chorea from grief/contradiction with sighs; < emotion; > alone; close to Mygal., but with sighing, lump-in-throat and fewer facial bites/grimaces [Farrington].
• Rhus toxicodendron — Restless, must move; but motions are willful to relieve stiffness; Mygal. is unwilled, inco-ordinate [Kent].
• Helleborus — Slowness, automatism; brain-fog chorea; Mygal. fast, snapping movements [Clarke].

Aetiology / Stage

• Dewey’s “post-scarlatinal chorea” group — Consider Mygal. when sleep stops, right side prominent, performance-worse [Dewey].
• Puberty/menses chorea — Compare Mygal. with Sepia, Lilium-t., Tarent.; choose Mygal. when erotism is absent and motor keynotes dominate [Farrington], [Clarke].

• Complementary: Zincum — Residual restlessness and school-weariness after Mygal. calms the storm [Kent].
• Complementary: Ignatia — Emotional shocks as triggers; alternates when grief/contradiction is the spark [Farrington].
• Follows well: Belladonna — In acute neuro-irritability post-fever, then Mygal. for the persisting inco-ordination [Clarke].
• Follows well: Agaricus — When chilliness and spinal aches fade but performance-worse chorea remains [Farrington].
• Precedes well: Tarentula — If, after Mygal., a strong music/dance modality appears or sensual mischief dominates [Clarke].
• Precedes well: Zincum — For lingering fidgety feet and mental dulness after storms have ceased [Kent].
• Antidotes: Nux-v. (over-stimulation, drugging), Coffea (sleepless irritability) in some schools [Boericke].
• Related group (Arachnida): Tarent., Therid., Latrod. — share sensory hyperaesthesia but differ in spheres (music/sexuality; noise/vertigo; cardiac pain) [Farrington], [Clarke].

• Post-scarlatinal/post-measles chorea with sleep-stops, right arm/leg dominant, and observation-worse: Mygal. first line; quiet room and cool air help [Allen], [Dewey], [Clarke].
• School chorea (handwriting/feeding wrecked by flings): steady the wrist while the dose acts; the patient often instinctively seeks firm support—a bedside confirmation [Farrington].
• Pubertal/menses chorea (girls): choose Mygal. when erotism and music-modality of Tarentula are absent; movements aggravated during the flow [Clarke].
• Potency & repetition: Low–medium (3X–6C–30C) repeated in active phases; step to 200C for sensitive, explosive cases once the keynote totality is clear; stop on steady improvement [Boericke], [Clarke].
• Pearls:
  • “Movements cease in sleep; return on eye-opening—child cannot eat or write—Mygal.” [Hering].
  • “Chorea worse when watched, better unobserved; darting tongue, facial grimaces” [Allen].
  • “Right-sided hand–foot scatter; firm support steadies for a moment—decides against Tarentula” [Farrington].

Mind

• Excitement aggravates chorea — observation/contradiction sparks flurries [Allen].
• Impulsive, hurried, cannot keep still when awake — hyperkinesis portrait [Hering].
• Shame from loss of control, prefers to be unobserved — performance-worse axis [Clarke].
• Irritability from failure of will to command muscles — paradox of intention [Farrington].
• Fright renews chorea — aetiologic clue [Allen].
• Better in quiet surroundings — nursing modality [Clarke].

Head/Face

• Head jerks side to side, backward; knocks pillow — motor scatter [Hering].
• Grimacing, features distorted; tongue darts and bites cheek — feeding impeded [Allen].
• Facial movements cease in sleep — diagnostic key [Clarke].
• Photophobia/bright room worse — sensory overload [Clarke].
• Nose and lips twitching with sniffs — choreic mask [Allen].
• Jaw snaps; teeth click — meal hazard [Allen].

Speech/Throat

• Speech jerky, words broken by grimaces — articulatory chorea [Clarke].
• Swallowing interrupted by throat spasm — liquids dribble at jerk peak [Clarke].
• Better small sips, unobserved — performance-worse nursing cue [Clinical].
• Attempts to speak aggravate movements — intention-worse [Hering].
• Chorea of tongue — darting, protruding, sudden withdrawal [Allen].
• Choking on effort to swallow during paroxysm — mechanical, not inflammatory [Clarke].

Extremities

• Hands in constant motion; cannot hold objects; right worse [Hering].
• Legs stamp, dance, kick; gait zigzag; falls from knee-jerks [Allen].
• Voluntary effort worse; restraint/firm support better (momentarily) [Farrington].
• Writing impossible during paroxysm — school chorea [Clarke].
• Movements cease during sleep — chain to general keynote [Hering].
• Renew on waking — sequence rubric [Clarke].

Generalities

• Chorea: awake only; sleep stops — capital rubric [Hering].
• Worse: excitement, contradiction, noise, bright light, warm rooms, on waking — modality cluster [Allen], [Clarke].
• Better: quiet, cool air, unobserved, firm support, pressure — bedside measures [Clarke], [Farrington].
• Right-sided predominance — lateral hint [Boger].
• After exanthemata (measles/scarlatina) — aetiologic rubric [Dewey].
• Puberty/menses worse (girls) — gynaecologic linkage [Clarke].

Sleep

• Movements cease in sleep — decisive [Hering].
• On waking, motions renew immediately — cycle [Clarke].
• Daytime drowsy pauses relieve briefly — microsleep effect [Clinical].
• Dreams lively but movements absent — state-dependent key [Allen].
• Better in dark, cool, quiet room — nursing alignment [Clarke].
• Noise reawakens jerks from drowse — sensory trigger [Allen].

Hering — Guiding Symptoms (1879): core clinical picture of chorea; sleep-stops; right-sided bias; modalities.
Allen, T. F. — Encyclopaedia of Pure Materia Medica (1874–79): collated cases; facial/tongue grimaces; performance-worse.
Clarke, J. H. — Dictionary of Practical Materia Medica (1900): aetiologies (post-exanthemata, puberty); nursing modalities; comparisons.
Boericke, W. — Pocket Manual (1901): concise keynotes (chorea, sleep-stops, right side).
Boger, C. M. — Synoptic Key (1915): differentials with Agaricus, Zincum, Cuprum; right-sided hints.
Farrington, E. A. — Clinical Materia Medica (1887): spider-group comparisons; performance-worse vs music-amelioration.
Hughes, R. — Cyclopaedia of Drug Pathogenesy (1870): toxicologic reasoning; arachnid group portrait.
Kent, J. T. — Lectures on Homœopathic Materia Medica (1905): chorea differentials (Stram., Hyos., Zinc., Cupr.).
Nash, E. B. — Leaders in Homeopathic Therapeutics (1899): clinical notes on post-infectious chorea.
Dewey, W. A. — Practical Homeopathic Therapeutics (1901): post-scarlatinal chorea grouping; management pearls.
Tyler, M. L. — Homoeopathic Drug Pictures (1942): bedside emphases; quiet/unobserved better.
Phatak, S. R. — Materia Medica (1941): terse keynotes (right-sided chorea, sleep-stops, excitement-worse).